New World Winemaker Blog

What’s in the bag?

Karien O'Kennedy — Fri, 03 Feb 2012 12:51:22 +0000

The cat is out of the bag so to speak. It seems that not all tannins are created equal and quality differences between suppliers exist. Best you make sure you buy from a trusted supplier…

I recently read an interesting (also from a date of publication point of view) article, published in a reputable scientific journal called: “Impact of exogenous tannin additions on wine chemistry and wine sensory character.” They analyzed the effects of a range of enological tannins in Merlot wine. First they analyzed how much of the product sold as tannin was indeed tannin. They found it to be “12 – 48%.” What is the rest of the stuff in the bag that you are adding to your wine??? They found that adding the recommended dosage of the supplier was too little to have a “measurable effect.” They then proceeded to add higher concentrations and concentrations exceeding the supplier’s recommendations. The latter did indeed have a measurable effect on the wine’s phenolic content but also had a “subsequent negative impact on wine sensory character.”

In case I misinterpreted the article, for which I then profusely apologize to all tannin suppliers, here is the link:

http://www.sciencedirect.com/science/article/pii/S0308814611013781

Your thoughts….

Karien O’Kennedy is the Online Communications Manager for Oenobrands. She also knows the odd thing or two about winemaking and fermentation.

This NewWorldWinemakerBlog.com post was written by Karien O'Kennedy

Consumers finally ask about alcohol levels

John Kelly — Fri, 20 Jan 2012 05:03:32 +0000

There’s little need for me to rehash the back-and-forth in the wine media regarding alcohol levels: in short, the wheel has turned and we are back in the 1980s when it was fashionable to criticize California wine for having high alcohol.

Here we are again. The difference this time around is that there is a hard number on the lips of the critical: 14%. The narrative being pedaled suggests that wines over this level generally are problematic, inferior, out-of-balance, not true-to-type, lacking: terroir, focus, complexity precision, nuance, etc.

I disagree.

And I’ve commented here and elsewhere that I have noted zero interest in the topic among the visitors to our Tasting Salon. But the “over 14% sucks” meme has a life of its own, it’s out there, it won’t die; sort of like “the President is a foreign-born Muslim.”

Because of this persistent media attention, I figured that it was bound to happen—sooner or later—that one of my guests was going to comment on the “high” alcohol levels on the labels of my wines.

It happened like this. Three nice people came in and tasted through the five wines I had on offer: three Pinots, a Châteauneuf-du-Pape-style blend and last, a varietal Syrah. They seemed to be enjoying them. After the Syrah one of the guests asked “What’s the alcohol on these wines?” I answered “between 14.5% and 14.9%” and a couple of them started muttering “oh, that’s high—so-and-so won’t drink it.”

I politely asked them if they could have guessed that the wines had alcohols approaching 15% without being told, and each of them admitted “no” they couldn’t have. One commented that “…these wines don’t taste hot.” I explained that ethanol doesn’t really taste hot, but that other alcohols do—propanols, butanols, pentanols, etc. and their esters and oxidation products, collectively called congeners in the distillation biz.

These fermentation products are more likely to be produced by yeast under stress, and high initial sugar as well as high final ethanol concentrations are potent stressors, as are nutrient and co-factor deficiencies. In my winemaking I go out of my way to minimize the stresses on yeast (though not so far as to throw diammonium phosphate—DAP, a source of ammonia—at every ferment) and so the levels of these congeners are low in my finished wines. No “heat” on the palate.

I further explained that in fact few of my wines finish fermentation much over 13.5%-14% but they pick up as much as 1%-1.5% during barrel aging. This is because we have a dry barrel cellar. Inside the barrel there is 86% water and 14% alcohol, while outside there is an average of 30% water and 0% alcohol. To a first approximation, the thermodynamic drive for water to leave the barrel is over 3x what it is for alcohol, and so over the course of 2+ years aging in barrel the alcohol level of the wine inside actually goes up.

A wine made from grapes harvested at “optimal” ripeness and put to barrel at 13.5%, in our cellar may well end up near 15% when it is ready to go to bottle. This is not the same as harvesting the grapes over-ripe. Not only do these wines not taste hot, they don’t taste raisined.

Anyway, the offshoot was that these folks bought a case of wine, and intended to put some of in front of their “I won’t drink any wine over 14% because wine over 14% all tastes the same” friends and see what they think. Awesome.

John Kelly is the owner and winemaker of Westwood Wines, Sonoma California. This blog was originally published on his blog: “notes from the winemaker” on the 3rd of January 2012 at 14h52 to be precise.

This NewWorldWinemakerBlog.com post was written by John Kelly

A brief look at the evolution of winemaking technology

Bernard Mocke — Fri, 13 Jan 2012 13:52:03 +0000

If you gaze upon these images for a few moments (some might need more time), you will notice a few things. Most significant is that things tend to not only get more colorful towards the end, but also more revealing. Those of you who aren’t too thrilled by the images above might wonder what scantily clad damsels have to do with the evolution of wine technology. Best you read on then.

During an ancient and alcohol fueled conversation, a chef expressed his discontent at the notion of wine research. His bottom line was that you cannot drink research. After a few moments of thought (which was remarkably difficult at that time), I pointed out the obvious improvement of wine during the past 100 years. Also the availability of science and technology allowing for the abundance of excellent wines which are currently available. Just like the evolution of the bikini, science allows you to make things more revealing. To strip things down to the basics and to fulfill a very important need…

Alcoholic fermentation by yeast is a natural and beautiful thing. One might even call it a simple process. Nonetheless, this seemingly simple process is governed by hundreds of thousands of elements, chemicals, enzymes and micro-organisms. Louis Pasteur, often called the father of microbiology, paved the way for the identification, enumeration and understanding of all micro-organisms. His humble beginnings in the early 1860’s allowed him to conclude that micro-organism can lead to wine, beer and milk spoilage. Back then, all germs were seen as the enemy. Who would have thought that more than 150 years later, we add specific yeast and bacterial cultures to wine in order to make better wines. You can practically get a wine yeast for any grape variety, winemaking condition and style that you desire. In 1953, James D. Watson and Francis Crick suggested the first correct double-helix model of DNA structure, which with ongoing research and refinement allowed us to study yeast genes and this helped us with the continuing selection and improvement of yeast strains for specific new world winemaking conditions.

Enzymes have also come a long way since their discovery in 1833 by Payen and Persoz, who treated an aqueous extract of malt with ethanol and precipitated a heat-labile substance which promoted the hydrolysis of starch. Nowadays, it is hard to imagine any commercial winery without the use of all the different enzymes. Not only do enzymes improve wine quality, but they also make life easier for the winemaker. For example, a settling AND skin contact enzyme like Rapidase Expression (Oenobrands) allows for a single addition at crushing of white grapes. Not only is varietal character enhanced, but more than ample enzyme activity remains after pressing in the settling tank.

Remarkable advances have also been made in cellar and wine treatment machinery. This is not surprising, seeing that our club wielding, cave-dwelling ancestors already tried their hand (or should I rather say claw) at winemaking back in the spry 4000 BC’s. The oldest known winery is located in the “Areni-1″ cave in the Vayots Dzor Province of Armenia. This winery, which is over six thousand years old, contains a wine press, fermentation vats, jars, and cups. Archaeologists also found grape seeds and vines of the species Vitis vinifera. Gravity was all the rage before pumps were designed, but there is a refreshing new push towards using gravity again in modern cellars.

Wine treatment was also not left behind. Where in the past, winemakers had to deal inventively with maladies such as high alcohol, volatile acidity, Brettanomyces-taint etc., the advent of reverse osmosis and spinning cones offers cost effective solutions.

Sir Francis Bacon said in 1597: “Knowledge is power.” Science allows humans to empower themselves. And to feel smarter. If you don’t believe this, just think of how smart you usually are after a few glasses of wine…

Bernard Mocke is a technical consultant for Oenobrands.

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

Reductive strength

Bruce Zoecklein — Thu, 15 Dec 2011 23:00:54 +0000

“The mystery of why some wines live and some wines die young should haunt every serious New World winemaker” – Randall Grahm Bonny Doon Vineyards

As discussed in previous postings, longevity may be considered within the pantheon of wine quality. The reductive strength of a wine is a measure of oxygen uptake and the ability to handle that uptake, that is improve with age. In red wines this is influenced principally by phenols and impacted by several winemaking protocols.

In a recent study (Kassas and Kennedy 2011) wines commanding the highest market value had several attributes in common including the highest concentrations of total tannins, the highest concentration of skin tannins and tannin-anthocyanin bound pigment polymers.

In grapes and wines, anthocyanin pigments can be either free monomers, that is, unbound, or associated with other compounds including phenols such as tannins to form polymers.

Tannin polymerization in fruit and wine continues until an anthocyanin molecule binds the terminal ends of the tannin chain forming ‘bookends’, thus stopping the polymerization. As such, the ratio of anthocyanins to tannins is important. This ratio impacts the extent of polymerization and, therefore, astringency.

Large tannin-tannin and tannin-anthocyanin polymers provide a relatively large number of binding sites to interact with proteins, as well as salivary proteins. As such, wines with an abundance of large polymers tend to lack softness and often possess a dry mouth sensation.

Conversely, smaller polymers have fewer protein binding sites and produce less astringency while providing a softer mouthfeel and often more palate depth. These smaller polymers are associated with enhanced reductive strength and wine aging potential.

Some phenols (diphenols) have the ability to react with oxygen, bind with another phenol, and recreate the original structure-thus allowing it to react over and over again. This helps explain the rather counter intuitive feature of exposing a young wine to oxygen and making that wine more resistant to oxidation. Young red wines can consume oxygen, actually increasing reductive strength.

Randall Grahm of Bonny Doon Vineyards in California considers reductive strength to be analogous to a wine’s chi or, as the Chinese say, life force. When a wine is young, it can share its chi with the world; when old, it must guard it so the wine does not diminish too quickly. Young wines have a capacity to adsorb oxygen and that can actually increase its resistance to later oxidation. Irrespective of chi, we believe that reductive strength is related to the phenolic composition of a wine and, therefore, to longevity.

“Experience is the name everyone give to the their mistakes” - Oscar Wilde

Dr Bruce Zoecklein is a Professor Emeritus, Enology-Grape Chemistry Group Virginia Tech.

His Enology Notes are available at www.vtwines.info.

This NewWorldWinemakerBlog.com post was written by Bruce Zoecklein

Why do we get hangovers?

Boela Gerber — Thu, 08 Dec 2011 23:00:23 +0000

It’s happened to the best of us and, unfortunately, we all know the feeling: Waking up the next morning, feeling like death warmed up and swearing you’ll never drink again. But what exactly is a hangover and what in wine causes hangovers?

For those who don’t know, common features of hangovers include headaches, nausea, fatigue, dehydration and weakness, even mild depression. I must admit I didn’t realize hangovers are that complex until I started to research them. It gets a little technical, I know, but hang in there – it’s pretty interesting!

The most common cause of a wine hangover is dehydration. Alcohol causes the body to lose water through a complex pathway, resulting in the brain temporarily shrinking. This puts the membranes under strain, causing a headache. This goes hand in hand with a very dry mouth. Furthermore, alcohol causes glycogen (your medium-term energy store) to be converted into glucose and excreted along with salts and minerals, causing you to feel tired the next day. Are you ready to open the next bottle of Chenin yet?

Another major cause of hangovers is biogenic amines, specifically histamine, a chemical we usually associate with allergic reactions. Almost all alcoholic beverages contain some histamine, especially red wine, as it is made from whole grapes. Some people are more sensitive to histamine than others, which can lead to allergic reactions. Symptoms may vary from rosy cheeks to bad headaches. This has nothing to do with the vast amount of wine they knocked back the previous night, of course… There are quite a few factors that can influence the histamine content of wine, and most of them are related to the microbial health of the wine. So, it is very possible that the red wine from one producer will be fine while the same variety from another producer will give you a splitting headache.

And then there is acetaldehyde, which is a by-product of the liver breaking down alcohol. The body can break down small quantities of acetaldehyde, but it cannot metabolize large quantities acetaldehyde, which adds to your hangover. Interesting to note here is that acetaldehyde is closely related to formaldehyde, the preservative that scientists use to store dodgy organs in jars. That really makes you reach out to your wine rack, doesn’t it?

Next is a group of molecules called congeners, which is commonly found in dark-colored drinks like red wine, brandy and whiskey. Very little is known about this chemical group, but apparently it is not very good for us, hence the hangovers.

Interestingly, in my research for this article, I found no mention of sulfur – one of the most popular culprits on which hangovers are pinned. Now you know what happens on the odd occasion when you lose the plot. Having said that, I still believe that moderate wine consumption will definitely add quality to your life and health. Cheers!

Boela Gerber is the winemaker of Groot Constantia wine estate in South Africa. This blog was originally published on www.conca.co.za.

This NewWorldWinemakerBlog.com post was written by Boela Gerber

Winemaking in the Rhineland-Pfalz: Part 2

Bernard Mocke — Thu, 01 Dec 2011 23:00:49 +0000

During my recent harvest stint in Germany, my host, Christoph Hammel uttered many memorable (and some that I am not allowed to mention here) pearls of wisdom. He told me about a meeting where some of the biggest names in German winemaking and professors associated with the wine industry were present. A very well know professor publically stated that his belief system does not have any room for the theory that yeasts impart any aroma to a wine fermentation. At this, Christoph got up and glibly replied: “My dear sir, it is not a question of belief. It is a question of knowledge.” The subsequent pandemonium that ensued was apparently quite noteworthy (hence the photo above).

Christoph is a big believer in using technology, specifically technology that can be used to make wine, and wine processing, better. Even more specifically, he is a big believer in additions. He always said to me that he makes wine that people want to drink and if this can be achieved with the addition of enzymes and other winemaking tools, so be it. Every addition that he does is done for a reason. One thing can be said with certainty and that is that Christoph believes in the “interventionist” approach to winemaking. A lot of winemakers like to claim that their wine is made “naturally” and with the least possible human intervention, but Christoph is at the complete opposite of the spectrum. He has some pretty far out and amazing ideas and some might even call him a renegade or a cowboy after hearing about his yeast mixing and addition regimes!

As far as the additions are concerned, Optiwhite (Lallemand) is one of his stalwarts. This is usually added at the beginning of fermentation. β-glucanase and β-glycosidase enzymes are added at the end of fermentation (at about 0°Brix). Depending on the structure and quality of a specific wine, ascorbic acid is also added right at the end of fermentation. DAP is added at three stages and is sometimes even added in divided dosages during the day, depending on the fermentation bouquet. In addition to DAP addition, thiamine is added to all musts. This is done simultaneously with sugar addition. It is well known that fungal infection on grapes depletes thiamine and it is therefore an excellent prophylactic measurement against stuck, sluggish or smelly ferments. For each addition, a cost to benefit decision is made. For instance, light and easy drinking wines will not get all the bells and whistles. The more expensive wines will get a full range of stuff added.

If Christoph was not such an excellent winemaker, I would have said that he missed his true calling in life: A chef! A chef who is forever mixing, adding and tasting, mixing, adding and tasting…

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

Introducing: Oenotools Winemaking Calculator

Patrice Pellerin — Thu, 24 Nov 2011 23:00:54 +0000

OENOTOOLS is the latest smartphone and tablet application to help winemakers make essential calculations during wine production.

This free application developed by OENOBRANDS contains the most widely used calculation and conversion tools required in the winery. The development of this application is in line with Oenobrands’ strategy of offering winemakers innovative, advanced winemaking solutions.

The first version of OENOTOOLS allows the winemaker to:

-Calculate the quantity of any powder, liquid or gas additive to add to a tank. For instance, OENOTOOLS will determine the amount of gum arabic, enzymes, tannins or any fining agent to add to a tank from a powder or liquid source.

-Determine the amount of sulfite to add according to the winemaker’s selected source (various concentrations or gas) to reach a set total, free and/or active SO₂target.

-Convert the common measuring units used for grape juice and wine: for example, liters into gallons, brix into sugar concentration, etc.

-Establish the conditions and flow rate for deoxygenation and decarbonization using nitrogen stripping.

The OENOTOOLS app provides a range of quick and accurate winemaking calculation tools in four languages: English, Spanish, French and Italian.

Get the OENOTOOLS App from the Apple iTunes App Store and Android Market by scanning the QR code below on your iPhone or Android device.

Dr. Patrice Pellerin is the Technical Manager for Oenobrands.

This NewWorldWinemakerBlog.com post was written by Patrice Pellerin

Snow blower on Enceladus

Bertus Fourie — Fri, 18 Nov 2011 09:49:57 +0000

Have you ever wondered where the circle around Saturn comes from? Interestingly enough it was discovered that one of the moons of Saturn, called Enceladus, is successful in shooting ice grains far enough to form Saturn’s ring…

Just as amazed as I was 12 years ago when I was introduced to Saturn, I was when Ice Jet came to clean some of my barrels. The technology was introduced to me a while ago, and we have decided to put it to the test.

The coopers come to your site with their mobile unit and remove the heads of the barrels to expose the inside of the barrel. And this is where I saw to my total amazement the biggest, deadliest blisters you can imagine! And I was even more appalled when I saw and smelled the puss that drizzled out of these opened wounds…I call on all winemakers to inspect your barrels, please! I have some understanding now of why barrel differences occur, why Brett spoils our wine, why volatile acidity increase sporadically, and, and, and…If only barrel inspection helped…older barrels with these types of blisters induce most of the nightmares in very expensive, barrel maturing wines!

How does this work? The CO₂ ice pellets are blasted onto the contaminated barrel surface at -79⁰ C and basically “delaminates” contaminants from the wood. Once the ice makes contact with the wood surface it, returns to its natural gas (CO₂) state and expands up to 700 times to create shock waves. This effect drives brittle materials from the surface as tartrate crystals and sediments are frozen, fractured and removed exposing original, unused toasted oak surface.

It removes not only sediment, but also contaminants on up to 99% of the interior surface of the barrel. Most bacteria and mold spores are removed, which leaves the barrel in a cleaner state than any chemical or physical process can.

During the ice blasting process a layer of wood between 0,5 and 1,2 mm is removed, exposing a freshly toasted oak surface to the next cycle of wine. This also restores micro-oxygenation as a result of restored porosity. As toasting during cooperage is typically up to 1 cm deep, there is no need for re-toasting after ice blasting.

In a major project testing this technology in the USA, very promising results were obtained. The tests showed that the treatment allowed the barrels to impart significantly more oak volatiles into the wine. The only volatiles, which showed lower readings, were guaiacol and 4-methylguaiacol, which is responsible for “smoky”, and “chary” flavors. Organoleptic evaluations found the treatment to result in wines with improved fresh oak, vanilla, butterscotch and coconut flavors, decreased smoke/char flavors and fresher, cleaner fruit.

It is not the cheapest way to clean barrels, but as sure as the ice circle around Saturn, the most effective and hygienic way to clean barrels!

Bertus Fourie is a winemaker, turned Enology lecturer and creator of the Barista coffee Pinotage.

This NewWorldWinemakerBlog.com post was written by Bertus Fourie

Science-based versus Empirical Knowledge

Bruce Zoecklein — Fri, 11 Nov 2011 10:40:01 +0000

“Experience enables you to recognize a mistake when you make it again.”
– Bob Steinhauer-former Director of Vineyard Operations, Beringer Vineyards, CA

The kaleidoscope of viticultural and enological choices winegrowers must make reminds us of the complexity of our industry and how rapidly our philosophy and practices have changed as new knowledge is acquired.

To move forward, not laterally, from one vintage to the next, we need to keep Ray Koch’s famous remark in mind, perhaps with a slight modification: “You cannot manage (understand) if you cannot measure.” Our challenges, therefore, in crafting fine wines, include the understanding of the following:

Environmental factors, vineyard management and fruit chemistry

Fruit chemistry and wine chemistry

Wine chemistry and sensory properties

To some, this mechanistic approach may appear to be contra natura, against their philosophical nature and against artistic winemaking. However, a resolution of the above relationships goes to a core belief – that luck is the residue of design. As John Fowles stated, “For what good science tries to eliminate, good art seeks to provoke – mystery, which is lethal to the one, and vital to the other.” However, art and science are supplementary. That understanding will allow us to follow an important mantra: keep things as simple as possible, but not simpler.

In order to optimally use both science and art, we must understand the difference between empirical or observational knowledge, and science-based knowledge. We must know the limits and merits of each. Empirical knowledge is sometimes faulty, because what may apply to one circumstance may not to another. The question is one of relativism. What information is universal, and what information is specific to time, place and circumstance?

As an industry, the distinction between science-based and empirical knowledge is sometimes blurred. What works at one vineyard site certainly may not work at another. We know this intellectually, but sometimes fail to keep this in mind. Another problem with relying solely on empirical observations is that, if two outcomes are similar, we have a tendency to assume they must have a similar cause. This may or may not be correct.

One of the steps that can aid in understanding the relative merits empirical and science-based information is to develop a HACCP plan. HACCP or hazard analysis critical control points, is a system for assuring product quality control from beginning to end, through the identification and monitoring of the critical control points (CCPs) during processing.

Dr Bruce Zoecklein is a Professor Emeritus, Enology-Grape Chemistry Group Virginia Tech.

His Enology Notes are available at www.vtwines.info.

This NewWorldWinemakerBlog.com post was written by Bruce Zoecklein

The Politics of Wine

Guy Webber — Sat, 29 Oct 2011 14:50:04 +0000

Winston Churchill once noted that: “Any man who is under 30, and is not a liberal, has no heart; and any man who is over 30, and is not a conservative, has no brains.”

Nelson Mandela, in his book, Long Walk to Freedom, also stated that it is natural for people to become more conservative with age – unfortunately I don’t have the exact quote here, but that was the gist of it.

When it comes to being outspoken, it is most often the youth who are in a league of their own. Extolling their own virtues is undertaken liberally and forthrightly and hearing their messages is easy, as they are shouted out rather than hinted at.

Quite often (unfortunately not always) the messages being shouted by the “upstarts” contain many truths, have been well thought through and are conveyed with the best intentions rather than with diplomacy.

As time goes by, many lessons are learned and more conservative approaches follow in conveying these messages. Loudhailers and street corners are exchanged for notepads and Boardrooms; engagement is preferred to statement and the importance of unity supersedes the egos of individuals. At this stage, the voices are softer, subdued and more intelligible and the messages, while often inherently similar, conveyed more subtly and convincingly.

While the two Gentlemen quoted above were obviously referring to more political conservatism than to the stages in the life of a wine, both ring very true when it comes to wine.

While young wines often tend to jump out of the glass at you with their vibrance and overt enthusiasm, older ones tend to be much more restrained, less obvious and thus a lot more complex.

Perhaps I’m just getting older myself, but I must admit that, whether I’m listening to politicians or enjoying a glass of wine, I much prefer being spoken to than being shouted at!

Guy Webber is the winemaker of Hill & Dale Wines, Stellenbosch South Africa. This blog was first published on their website 24 August 2011.

This NewWorldWinemakerBlog.com post was written by Guy Webber

Organic Is Better, Right?

Bruce Zoecklein — Fri, 21 Oct 2011 14:09:08 +0000

There is no word for winemaker in French, Spanish, Italian or German, pointing to the ingrained belief that wine is made by nature, not by man. The conviction has been held for centuries in the Old World-that wine is, at its core, the reflection of a place. While there is no single-word translation of terroir into English, the French will often use this one word to explain why a wine tastes the way it does, as a result of its place. This is a basis for a present-day concern: Is industrialization muting the effect of place?

The consumer is left to answer the questions: Did this fine wine I am enjoying come from a great vineyard in a top appellation, from a talented winemaker using some dazzling new technique, and/or from a slew of agricultural and/or processing chemicals?

The sense of place is a concern as the world and its products become industrialized, sparking renewed interest in chemicals used in our foods, including wines.

A capstone event occurred in 1990 in theUSwith the Alar episode. Alar, a growth-regulating chemical widely used in orchards at the time, was later listed as a carcinogen. The consumer’s negative reaction was a potent catalyst for the organic food movement. The question of whether agricultural chemicals are good or bad was catapulted to the forefront inAmerica, and remains.

Currently, there are at least two theories as to why the lack of chemicals may be a good thing (beyond the purely psychological), both relating to the production of so-called secondary plant metabolites, that is aroma, flavor and phenols.

Plants produce these for several reasons, including defending off pests and disease. Some believe that plants defended by man-made chemicals do not need to work as hard to make their own natural pesticides, such as phenolic compounds. They do not need to expel their limited energy producing as many secondary metabolites.

Another theory suggests that soils that have been significantly altered with chemicals are simpler. While they may contain the required NPK etc., these soils may not contain all of the raw ingredient precursors that plants need to produce the vast array of secondary metabolites in optimum quantities or proportions.

There is some scientific evidence for both of these theories. For the wine industry, however, the question comes down to wine quality. To date, there have been few studies that suggest that the lack of approved chemicals consistently produce better wines.

Not using chemicals, particularly agricultural chemicals, sounds great and is certainly consistent with our general notion of sustainability. Unfortunately, there remains a void of scientific data suggesting that not using chemicals improves wine quality. Unfortunately, at this time the choices may be like the old joke:

I have theory that it’s impossible to prove anything – but I cannot prove it.

Dr Bruce Zoecklein is a Professor Emeritus, Enology-Grape Chemistry Group Virginia Tech.

His Enology Notes are available at www.vtwines.info.

This NewWorldWinemakerBlog.com post was written by Bruce Zoecklein

Winemaking in the Rheinland-Pfalz

Bernard Mocke — Fri, 14 Oct 2011 09:14:33 +0000

“Don’t make a big monkey dance about choosing a yeast, just decide if you want esters or thiols!” This is one of the more memorable sentences that was uttered by Christoph Hammel during my recent harvest stint at his cellar in Germany. Before I put this sentence into context, I should mention that the Hammel Weingut has been in business since 1723. This proud winemaking tradition is continued by veteran and outspoken winemaker, Christoph Hammel. His skills include a combination of modern thinking, creative planning and solid experience based on many years of making wine with a scientific yet artistic touch.

Christoph is such a staunch believer in Anchor Wine Yeast, I guess that you could even call him an Anchorfile. He has repeatedly achieved success on a variety of grape varieties such as Grüner veltliner (fermented with Anchor Exotics and Anchor Alchemy I), Scheurebe (Anchor Alchemy II), Sauvignon blanc (Anchor Alchemy II), Dornfelder + Portugieser Rosé (Anchor Alchemy I and II), Müller-Thurgau (Anchor Alchemy I), Chardonnay + Weissburgunder (Anchor Alchemy I) and Sylvaner (Anchor VIN 2000), Riesling (Anchor VIN 13 and Anchor Exotics). Of special interest will be some the combinations of yeasts that Christoph likes to co-inoculate, such as VIN 13/NT 116 (also Anchor) and VIN 13/NT 116 together with Laffort X5. I have seen that these combinations have a massive effect on floral, fruity and tropical aromas, but no negative effect on fermentation kinetics.

Alex Halberstadt has the following to say about Sylvaner: “Nobody dreams about Sylvaner. Mentioning it in a group of wine people is akin to professing an interest in the finer points of cardboard fabrication. The grape bums people out.”

However, even a neutral grape variety such as Sylvaner stands to gain from these mixtures. For example, I inoculated Sylvaner with NT 116/VIN 7/X5 (as per Christoph’s instructions). Some of the tasting notes that I made over the course of the fermentation were: “tea leaf, fig, apple, floral, banana, grapefruit, spicy, curry, herbal, white pepper, grapefruit, and apricot”. In theory a more complex wine is possible because of the ester and thiol production of these yeasts and this is exactly what you’ll get in real life!

Something else that Christoph does, is oxygenation of the must and water mixture during yeast rehydration. In the photo below, you’ll see the white bin in which yeast is rehydrated and behind the bin you’ll see an oxygen tank.

Typically, the rehydration mixture is cooled down at 5ºC increments (with ample time intervals) until a temperature difference of approximately 5ºC is observed between the rehydration mixture and the must to be inoculated. Note that during all this, the rehydration mixture is continuously oxygenated by adding a steady trickle of oxygen. The rehydrated and happy yeast is then simply pumped to the tank in question. Christoph swears by this method and cannot remember the last time he suffered a stuck ferment. For more information on the science behind this, you are welcome to read my previous blog titled: “Is your yeast on sterols?”

More to follow…

Bernard Mocke is a technical consultant for Oenobrands.

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

When did wine become “unnatural”?

Sakkie Pretorius — Fri, 07 Oct 2011 11:19:29 +0000

It is a question worth asking, given today’s debate about “natural” winemaking practices. The message is confusing leaving consumers baffled. The answer requires a review of 7,000 years of wine-making history. The first fermentation, for example, was more likely the result of serendipity rather than design. Spontaneously, damaged grapes fermented in harvesting pots and mystified farmers tasted wine for the first time.

Those same farmers enjoyed the taste of their creativity, and its effects. They became fascinated by the difference between fermented grape juice and unfermented fruit. They went on to investigate, making empirical observations. They sought to harness natural events and biochemical reactions in repeat “experiments” which could describe early “vintages”, today.

The foundations of science and technology – and biotechnology, in particular – were therefore established and since then, scientific knowledge has grown at an exponential rate. There have been breakthroughs in chemistry and biology, transforming our understanding of the natural world as we know and understand it – or believe that we do.

Yet, throughout history wine has retained a mythic aura, cloaked in mystique. Maybe that is why Louis Pasteur said: “A bottle of wine contains more philosophies than all the books in the world.”

But winemaking is not a matter of chance or magic. Left entirely to nature, the result is variable, unreliable and can be undrinkable. The completely natural result of fermenting grapes is vinegar.

So how is wine made? It is created through a process of fermentation using the right yeast, nourished by the right nutrients. Louis Pasteur was the first to discover this in the late 1800′s. Before his discovery, no one knew that yeast played a role in the production of alcohol: there had been little progress since the time of the ancients. Winemakers knew that fermentation happened spontaneously after fruit was crushed but the results were variable: sometimes the result was wine, sometimes it was vinegar.

Wine is not, therefore, a “natural” product – not in the form we know it. Every decision the winemaker makes (or fails to make) affects style and quality. Wine does not make itself. And never before has there been so much opportunity for the winemaker to direct viticulture and vinification to shape wine according to consumer preferences.

But the pressure is on. There is heated argument as to whether today’s wine is better – due to the contribution of scientific knowledge, technology and research – or whether so-called “natural” wine is better. There is a new-found nostalgia for the wine of yesteryear made with a minimalist approach.

Proponents of “natural” wine reject, for example, “interventionist” practices that prevent oxidation and microbial spoilage. They oppose the use of ingredients to correct balance, or the use of enzymes to aid fermentation. They reject the application of cultured yeasts to avoid the risk of stuck ferments and off-flavors, and they oppose filtering and fining to remove potential impurities. These are the marks of “industrial” products, they say, not “natural” wine.

On the other hand, wine researchers are frustrated by such arguments, waiting to uncork the next-generation of technical innovation. As they have done through history, wine’s innovators are keen to assist in the crafting of unique, stand-out wines that meet ever-shifting consumer expectations while underpinning profitability and sustainability.

The truth is that winemaking is both art and science and always has been. The supposed dichotomy between “natural” and “unnatural” wine is a false one.

Professor Sakkie Pretorius is the Managing Director of the Australian Wine Research Institute (AWRI).

This article first appeared in the July 2011 edition of The Adelaide Review.

This NewWorldWinemakerBlog.com post was written by Sakkie Pretorius

Stinkpots

Bertus Fourie — Fri, 30 Sep 2011 07:28:57 +0000

Now you probably wonder what old Jack Sparrow had to do with this…Interestingly enough, Stinkpots, favorite weapons of pirates, were malodorous concoctions made from saltpeter, limestone, asafetida (a vile-smelling gum resin), and decayed fish that were packed into earthenware jugs, ignited, and hurled onto an enemy ship…

Most of us had to manage a stinkpot brewing in our cellar at some stage of our lives, whether it was a result of a power failure (load sharing for South African winemakers), too little nitrogen, or just a general struggling yeast population. And then of course, if the H₂S turns into mercaptans… it will just about kill any odorous component remotely smelling of fruit.

H₂S contains sulfur in its most reduced form. Mercaptans are common organic compounds. When aerated, mercaptans can be oxidized to disulfides, which slightly change their sensory threshold and character. The oxidized forms are usually less of a stinkpot. These reductive components have unpleasant odor descriptors, and these can increase post-fermentation. Some of these, such as H₂S and mercaptans, react with copper and can be removed by copper additions, usually in the form of cupric sulfate. In some wineries additions of cupric sulfate is a standard procedure, sometimes with an addition of inactivated carbon. All of us are aware of course that such an addition, particularly on Sauvignons, can reduce the concentration of aromatic thiols with up to 20%… I personally believe a slight element of H₂S might actually contribute to the complexity of Sauvignon blanc.

But what to do? Well, the magic potion arrived in the form of inactivated yeasts impregnated with copper – Reduless®. It can be suspended with water and added to the tank directly after primary fermentation. The wine is racked off the lees after 72 hours. No residues, no potential risk of copper casse forming, but only a fresh smelling, wonderful wine. It has been developed by Lallemand for red and white wines to reduce H₂S, DMS, DES and other stinkpot related off-flavors in wine.

Bertus Fourie is a winemaker, turned Enology lecturer and creator of the Barista coffee Pinotage.

This NewWorldWinemakerBlog.com post was written by Bertus Fourie

What constitutes a high quality wine? Part 2

Bruce Zoecklein — Fri, 23 Sep 2011 08:44:55 +0000

What are the characteristics of a great wine? The following are a few features of a great wine adapted, in part, from Robert Parker (2008). Which of these do you agree with? What would you add or delete?

The ability to please both the palate and the intellect. Great wines should offer satisfaction on a hedonistic level, and challenge and satiate the intellect. There are many delicious wines that appeal to the senses, but lack profundity. The ability to satisfy the intellect is subjective, but experts often prefer wines with multiple dimensions, both aromatic and flavor.

The ability to hold the taster’s interest. Profound wines could never be called monochromatic or simple. They hold interest, not only providing an initial tantalizing tease, but possessing a magnetic attraction due to their aromatic intensity and nuance-filled layers of flavors.

Ability of a wine to offer intense aromas and flavors without heaviness. In some parts of the New World it has been easy to produce wines that are oversized, bold, big, rich, but heavy. It has been said that Europe’s finest wines have intense flavors without heaviness.

The ability of a wine to taste better with each sip. Most of the finest wines are better with the last sip than the first, revealing more nuances and more complex aromas and flavors as the wine unfolded.

The ability of a wine to improve with age. Many consider longevity an indisputable characteristic of great wines. Some suggest their wines will age when they mean their wines will survive. They can endure in the bottle, but are much more enjoyable in their exuberant youthfulness. If you open a bottle and drink a glass and replace the closure, a wine with longevity should stay fresh for the better part of a week. Most New World wines are generally dead the next day, while many of the finer Old World wines are not. Why? To varying degrees, wines consume oxygen. Likely, longevity has to do with reductive strength or resistance to oxidation. Reductive strength is linked to the phenol content, lees involvement and possibly the nebulous concept of minerality (See Enology Notes #160). Minerality, or capacitance is thought to give the primary flavor a sense of soulful depth or relief, providing a shadow or added dimensionality. This could relate to a number of viticultural parameters and practices, including soil and the biological nature of the soil. This has been described as petrichor, the smell that a new rain liberates from rock. Others describe this as an almost electrical-type buzz provided by the wines finish. Some believe that this resistance to oxidative change is a sort of Rorschach test.

Whatever definitions of wine quality we adopt, we need to continue to evaluate our products and assure ourselves that our knowledge is increasing from one season to the next.

Art is not the cultivated taste; it is the cultivation of taste – Nikki Giovanni

Dr Bruce Zoecklein is a Professor Emeritus, Enology-Grape Chemistry Group Virginia Tech.

His Enology Notes are available at www.vtwines.info.

This NewWorldWinemakerBlog.com post was written by Bruce Zoecklein

What constitutes a high quality wine? Part 1

Bruce Zoecklein — Thu, 15 Sep 2011 23:00:42 +0000

What is a great wine? Is it enough to simply provide naïve pleasure, or must a wine make an eloquent statement? Wine is art and as Jean Anouilh stated-the object of art is to give life a shape. To many in the wine world, real wines convey a sense of place, a genuine originality. The relativity of experience impacts one’s evaluation. Greatness in wine is much like a profound expression of art or music, depends upon personal experience and is subjective. Even though there is no singularity, definition greatness in art, music, or wine, though difficult to define precisely, enjoys a broad consensus.

Sensory evaluation is subjective. Like many of the finest things in life, however, there is considerable agreement as to what represents high quality. As Robert Parker states “No one should feel forced to feign fondness for a work of Picasso or Beethoven, much less a bottle of 1961 Latour.” Exceptional wines emerge from a philosophy which often includes the following:

Proper varieties planted in the correct climate; expression of the vineyard’s terroir; purity and characteristics of the grape variety or blend to be faithfully represented; and minimalistic winemaking.

Most consider that the world’s finest wines emanate from fruit grown in well-placed vineyards with microclimates favorable to the specific varieties. There is no such thing as the best grape or best clone, simply one well-suited to its growing environment. In the US, consumer’s palates are not tuned to terroir. We want jammy fruit, lasting intensity. Such wines may fool our senses in the same way that our primary physiology responds to the fat in a McDonald’s hamburger. Many of these are “feel good” products, the vinous equivalent of comfort food (Randell Grahm of Bonny Doon Vineyards). Is this bad? No, not as long as they are well made. They can obscure our link to the vineyard, if a host of addition products are employed. Such obscurity may limit the pace of industry development. Such wines appeal to a certain attitudinally-challenged denominator and may be a key link to our biological predisposition to favor fruit over complexity.

Some equate quality with quantity. This is true, regardless of whether we are talking about degree of ripeness, oakiness, or tannins. Are we making wines that are easy to like, but sometimes difficult to love? Perhaps we need to concentrate on means of adding some texture without deforming the ethereal essential character of a wine. We should not have the illusion that we can or should control everything. Minimalistic winemaking philosophy, when possible, allows for an intrinsic character, so that what is placed in the bottle represents as natural an expression of the vineyard, variety, and vintage as possible. This requires restraint in the use of adjuvants, cold treatments, and filtrations.

The greatest obstacle to discovering the truth is being convinced that you already know it.

Dr Bruce Zoecklein is a Professor Emeritus, Enology-Grape Chemistry Group Virginia Tech.

His Enology Notes are available at www.vtwines.info.

This NewWorldWinemakerBlog.com post was written by Bruce Zoecklein

Gone with the wind

Bertus Fourie — Fri, 09 Sep 2011 09:36:30 +0000

When in 1939, Rhett Butler quoted the memorable “how fickle is woman…” he obviously did not have any idea how complex consumers can be…But if one thing is true about consumers, it is the fact that they demand top quality for no dollars!

What does the consumer want? I reckon 99% of consumers want drinkability in what ever they may take from the shelve. And “drinkability” is one of those abstract terms with so many meanings and definitions. For me drinkability is a function of how well the winemaker interpreted the phenolic personality of a given block (or cultivar), and how the processing dynamics were being managed early in the life of the wine to obtain a wine which has loads of fruit, and soft and subtle tannins which are protected by complexing factors such as mannoproteins and colloids.

There are numerous ways to achieve this, and we know what important role oxygen plays not only in achieving this, but also in increasing the viability of yeasts and getting rid of bad flavours like H₂S. Various winemakers have experience with a number of cap management regimes, but in most instances various levels of oxygen is incorporated in the process. Obviously different strokes for different blokes.

Pulsair is one of these techniques. I stumbled upon this technology at an exhibition almost six years ago. More recently I saw fixed installations and even handheld units at various cellars in Australia. Yalumba has a fixed system on most of their red fermentation tanks.

How does it work? It works on the sequential release of compressed air or gas at the bottom of a tank for the purpose of creating circulation and mixing. Measured amounts of high pressure air are injected under flat round discs called accumulator plates installed on the tank bottom. It looks just like a creepy crawly. These released bubbles become bigger as they rise to the surface, and bubbles through the cap mixing the fermenting must very efficiently with the pomace.

The result? Soft luscious wines with loads of fruit.

I think winemakers should think a bit more out of the box when it comes to buying expensive oak barrels, and perhaps think more about savings down stream. The clever application of simple technology can certainly swing the bottom-line.

See pulsair in action on YouTube

Pulsair cap management

Pulsair red winemaking

Bertus Fourie is a winemaker, turned Enology lecturer and creator of the Barista coffee Pinotage.

This NewWorldWinemakerBlog.com post was written by Bertus Fourie

Are your yeasts on sterols?

Bernard Mocke — Fri, 02 Sep 2011 11:46:51 +0000

Recent crackdowns on doping in sport have made all of us more aware of the effects of performance enhancing supplements. This got me thinking. What if winemakers could come up with a legal magic potion for yeast? Like the magic potion that enabled Asterix and Obelix to defeat the Romans time after time. Something that would give mere mortal yeasts super human (rather super yeast) qualities?

An increasing worldwide trend is longer “hang-time”. Delaying harvest might increase berry aroma and decrease acidity, but it creates a unique problem for our little athletes. Increased sugar leads to increased alcohol levels in wine made with these grapes. Fermenting yeast thus run the risk of being smothered in the alcohol they produce as a result of them snacking on sugar. Fortuitously, there is a magic potion that you can give your yeast to boost their viability during fermentation.

First, let’s look at the definition of sterols: “Any of various alcohols having the structure of a steroid, usually with a hydroxyl group (OH) attached to the third carbon atom. Sterols are found in the tissues of animals, plants, fungi, and yeasts and include cholesterol and ergosterol.” Here comes the interesting part. Sterols and unsaturated fatty acids (UFA’s) are survival factors during fermentation, but oxygen is needed for the synthesis of said survival factors. With insufficient amounts, the yeast cell membrane functions poorly, especially during highly anaerobic conditions and especially with increasing ethanol levels. Inadequate sterol concentrations around flux controlling proteins in the yeast cell membrane cause damage to the cell membrane and ultimately results in cell death (read: stuck or sluggish ferment!). The key role between oxygen and sterols now becomes evident. Simply put, controlled and timely oxygen addition = more sterol synthesis = better ethanol resistance = happy yeast = happy winemaker.

In my previous life, I’ve found it useful to add oxygen to red ferments anytime from a third of the way through alcoholic fermentation, up to halfway. This roughly corresponds with the end of the cell growth phase and research has shown that an oxygen addition of five to ten mg/L has a very positive effect on cell viability. Another trick is to combine oxygenation and nutrient addition with a pump-over or punchdown. Complex yeast nutrients contain inactivated yeast, which is a good source of sterols. The abovementioned trick also counteracts reductivity, which every winemaker deals with at some stage.

Research is ongoing to gain more insights into how yeast sterol uptake and synthesis affects cell viability. Ergosterol is one of the main compounds being studied, but I’ve also read a paper which outlines the addition of cholesterol to a fermentation! Fermenting yeast are just as happy with cholesterol as they are with ergosterol, but I seriously doubt if winemakers will be chucking cholesterol by the bucketful into their wholesome red wines!

Bernard Mocke is a technical consultant for Oenobrands.

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

Flash Gordon in hot water after colour extraction incident at winery!

Bernard Mocke — Fri, 26 Aug 2011 10:26:14 +0000

If the title of this blog caught your eye, my ploy worked. Please accept my apologies; Flash Gordon will not be featured here. Or any other superheroes, for that matter. I will however elaborate on Flash Détente and its super colour-extraction abilities.

Of late, growing interest in colour extraction (especially in California) has led to the evolution of thermovinification into Flash-Détente. During thermovinification, the temperature of crushed red grapes is raised to 60˚C for anything from one to 24 hours. Thermophiles (pardon the pun) claim that increased tannin and colour extraction is to be had with thermovinification. The logic behind this is sound, as the high temperature breaks down cell structures. This in turn releases pigments, tannins and volatile compounds in the absence of ethanol. In the absence of alcohol, chemical bonds are formed between anthocyanin pigments and other phenols which stabilizes colour in the resulting wine. Should this concept give you cold feet, you might want to opt for cold soaking. During cold soaking, crushed grapes are soaked in their own chilly juices and pumped over for a few days in an effort to extract more colour.

Not impressed yet? Enter Flash-Détente, which is basically thermovinification on steroids. Grapes are briefly (two to five minutes) heated to 85˚C and then cooled in a vacuum. Cell walls pop, juices fly and a myriad of aroma and colour compounds are released. The vaporised water (with volatile compounds trapped within) is then chilled in a condensing column, after which the winemaker is left with the decision of adding the fluid fraction back to the main tank or not. Seeing that this condensate is full of pyrazines and in the case of lower quality grapes, rot and mold aroma compounds, the winemaker usually discards the condensate. This is however a double- edged sword, as varietal and fruity aromas is also lost in the condensate. Then again, the heat application inhibits enzymes such as polyphenol oxidase and laccase, which are often present in lower quality grapes. The effect of this heat on Brettanomyces is still ambiguous. Other benefits of extracting colour earlier are; improvement of purple hues in wine, fermentation at lower temperature and usage of different yeast strains. It is also speculated that the softer and rounder tannins are better extracted with water and heat, while the harsher tannins might be brought out where ethanol is the solvent.

Many traditional winemakers believe that Flash-Détente is for higher yield facilities, where often quantity outweighs quality (sic). It has been said that the loss of varietal character often results in a one-dimensional, soulless wine. As with all other winemaking decisions, the decision to go with or without thermovinification is an important one. Current studies on thermovinification are focusing on changing tannin concentrations in must with an increase in temperature and how varietal character is affected.

With a price-tag of $2 million for a Flash-Détente set-up, winemaker experience will be key in the decision to employ this system or not. Like they say, talk is cheap.

Bernard Mocke is a technical consultant for Oenobrands.

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

Wine fit for vegans and allergy sufferers

Louis Nel — Fri, 19 Aug 2011 08:29:21 +0000

The European Union might want to ban wine in which hen’s eggs or dairy products have been used, as some people can be allergic to these products. Alternatively the new law might just insist on labelling the wine as containing these products. The prevalence of allergic reactions to milk and egg products has been reported to be 1% of the adult population. Clinical trials have been inconclusive, and although wine has no history of causing allergic reactions as a result of the protein fining agents used, the possibility still exists.

Eggnog is a traditional drink at Christmas in the USA, and was developed in Europe by combining eggs and alcoholic drinks to let the eggs last longer. The drink was apparently first called “egg-and-grog”, and it has been known to cause allergic reactions in individuals. This seems to be the basis of the fear of egg allergens in wine.

Although HACCP is widely practised in the winemaking industry, almost all of the CCPs (critical control points) have a quality influence. There is only one commonly established real CCP and that is at bottling, to prevent glass from entering the bottles which could be harmful to people who swallow it. Another critical control point was once established to be grapes infected by Ochratoxin A, which is formed by moulds on grapes, but that is not very common.

The allergen law requires wine that contain these products to be labelled, but if there are no residues, who will be the wiser? The naughty compounds in eggs are the proteins that can easily be removed, although milk might leave residues of lactose. The ELISA tests that are used to test for residues cannot test down to zero, but the limits of detection have been found to be good enough to establish risk. There are also people with the view that if a product has been used, if it is still present or not, it must be stated.

There have been companies peddling plant alternative proteins that can apparently perform the same tasks as egg and milk proteins, but I have not had the pleasure to test these.

The new allergen labelling laws were originally intended to be implemented in 2005, but the deadline has now been extended to 30 June 2012, to assess possible exemption of these products. Let’s see what happens.

Louis Nel is the owner and winemaker of Louis wines in South Africa.

This NewWorldWinemakerBlog.com post was written by Louis Nel

Why an alternative to bentonite might help save the world…

Bernard Mocke — Fri, 12 Aug 2011 13:00:24 +0000

Nowadays, going green is all the rage. People are driving electric cars, industrial carbon dioxide emissions are scrutinised and even flatulent cows are not escaping the wrath of greenies. So what does this have to do with the wine industry?

I’ve recently learned that bentonite is a big culprit, leading to wine losses equivalent to that of New Zealand’s annual white wine production. This loss of 1-3% represents 120,000-360,000 tonnes of grapes. The related liberation of greenhouse gases for irrigation, harvesting, pressing and processing of this amount of grapes was estimated at 36,000-225,000 tonnes of carbon dioxide per year. Unfortunately for mother nature, bentonite fining is an effective and simple method for the removal of haze-forming proteins.

Apart from wine that is trapped and lost in bentonite lees (up to 3%, even with subsequent rotary drum vacuum filtration-RDV), a considerable reduction in varietal character is also inadvertently effected when bentonite fining is done. It is well known that aroma and flavour molecules in wine can be adsorbed by bentonite, which in turn leads to an unwanted decline in wine quality. Further oxidation during recovery from the bentonite lees merely adds to the aforementioned decline.

Before you go on a witch-hunt and banish bentonite from your cellar, there is good news. It was found that in-line dosing in conjunction with RDV can significantly decrease wine losses. A short description of in-line dosing: Untreated wine is pumped from a storage tank to an injection point, where bentonite slurry (supplied from a slurry tank) is continuously injected into wine or juice. A static mixer disperses the slurry, ensuring even contact between wine and bentonite. A contact period of five minutes in pipe work is allowed before centrifugation is used to separate wine and bentonite. The problem with in-line dosing is that it is not yet widely used and installation can be costly.

Batch fining combined with RDV remains the most popular method in countries such as France, Italy, Spain, California (ostensibly a country), Australia, Germany, South Africa and New Zealand. Collectively, their white wine production represent 40% of all wine produced globally. The amount of bentonite required for protein stability varies according to a number of factors, such as year, fruit type and growing region. The report that I studied in Grapegrower and Winemaker Magazine (in preparation for writing this blog) indicated that with all factors taken into account, a dose of one gram of bentonite per litre of white wine will be assumed.

Let’s have a look at some more numbers relating to the use of bentonite in the above mentioned countries. They produced 80% of all white wine in 2008/2009 and revenue loss was more than US$820 000 per year. If the value of domestically sold wine is added to the export values of white wine, the aforementioned figure climbs to a staggering US$1 billion!

The scourge of pollution is slowly suffocating earth and with an estimated 80-250 million kWh energy requirement annually, we can’t afford not to research alternatives to bentonite fining. Keep watching this space!

Bernard Mocke is a technical consultant for Oenobrands

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

Teaching your grandmother to suck stones

Jonathan Snashall — Thu, 04 Aug 2011 23:00:38 +0000

Passing down the wisdom of (perceived) minerality in wine is becoming increasingly suspect – even for died in the wool terroirists. No lesser being than Rhône-ranger Chapoutier has declared that ‘petrol’ characteristics are a winemaking fault saying they are a result of hard pressing of decomposed veins within the grape.

Comparing the debate over petrol aromas in Riesling to the issue of spoilage yeast Brettanomyces, Chapoutier said it is absurd that “historical defects in wine should be accepted as part of the character of the wine” and that the vital aspect of Riesling vinification is the gentlest of pressings, often taking 12 hours, so as to avoid breakdown of the vascular structure within the grape. The Chapoutier family also make Riesling in Alsace and Victoria (Australia).

Scientists are also challenging the notion that terroir can be detected in a wine. As part of a study into vineyard soils, the Geological Society of America concluded that the French ‘gout de terroir’ – translated literally as ‘taste of the soil’ – probably isn’t caused by minerals found in the vineyard. ‘If wine lovers are going to talk about a mineral taste in wine, they should acknowledge that we don’t at present know its cause”, says geologist Alex Maltman.

And they say the concentration of minerals in wine is below the threshold of human taste and smell. “I am not saying that chemistry and geology have no effect on the wine. It may have effects that we don’t understand. But whatever ‘minerality’ in wine is, it is not the taste of vineyard minerals,” said Maltman.

The argument that minerality is a product of mysticism, stones and established commercial interest is supported by the absence of hard scientific evidence. Renowned vineous academic Dr Seguin’s research found that the best terroirs covered extremely diverse soils, while the common themes are that none of the soils are very fertile, none suffered mineral deficiencies, and that these soils regulated water supply to the vines in such a way that it was nearly always just moderately sufficient.

The nod toward climate is that the greatest expression of terroir occurs when grape ripening is relatively slow, therefore late in the season, i.e. cooler climates.

While economists and statisticians are regarded with some scepticism for interpreting data for a pre-determined result, The Economic Journal found that terroir plays no part in the production of great wines. Two European academics – including a Frenchman whose whereabouts is now probably in question – collected data on environmental conditions and wine making techniques across the vineyards of Haut-Medoc, a classic example for terroirists, and concluded that wine making technologies, not terroir, determine the quality of wine.

The French claim that there is no good substitute for terroir looks at best highly exaggerated the professors said, at worst, terroir has no influence and the right combination of weather, vines, technology and chemistry are sufficient.

The irony – as all grandmothers now – is that soil minerals, in the right combination and concentration, are the only minerals that count.

Jonathan Snashall (wholebunchpress) is a winemaker (sometimes), freelance writer and foodie. He also writes for his own blog: hunter gatherer vintner.

This NewWorldWinemakerBlog.com post was written by Jonathan Snashall

Gold medal winemaking in La Mancha!

Patrice Pellerin — Fri, 29 Jul 2011 08:01:53 +0000

The cooperative Vinicola de Villarobledo has been the only winery from La Mancha region to win a Gold award at wine contest – Nuevo Vino 2011 – held in Madrid on the 15^th of June this year. This was the first time the cooperative winery presented a wine to this contest.

Martin Pardin (technical director of the cooperative) explains he wanted to innovate and create a very complex and unique red wine, adapted to modern demand for fruitiness, roundness and complexity in red wine. Grapes from Syrah, Tempranillo and Garnacha were partially destemmed, crushed and barrel fermented separately in 3^rd fill French oak barrels. Martin used an extraction enzyme and a new yeast from Oenobrands, Anchor Exotics SPH, in all barrels. This yeast is an interspecies hybrid between Saccharomyces cerevisiae and Saccharomyces paradoxus. It is the only yeast of its kind worldwide. Fermentation took ten days at temperature range 18-27 °C, with four hand pigeage daily. For yeast nutrition, Biovin (bio-regulator of La Littorale) has been added after density of 1040. Martin was very happy with the results obtained with Anchor Exotics SPH as it satisfied his need to create a “highly fruity and complex red wine, different from a standard red wine of La Mancha region”.

Malolactic fermentation started spontaneously immediately after alcoholic fermentation and was completed within one month. The wines from the three varieties were blended and stored for five months. No fining was applied before bottling and Mannostab (Laffort) was added to secure tartrate stability.

Martin is very happy with the recognition this award gives to his winery and region, since all the other wines awarded came from other prestigious Spanish wine regions. He plans to increase production with his approach and will continue use of Anchor Exotics SPH as “a perfect tool to help him achieve complexity and fruitiness “. At the moment the wine is only available for sale in Spain but an extension of production in 2011 will allow the winery to have the wine available for export markets.

Patrice Pellerin is the technical manager for Oenobrands.

This NewWorldWinemakerBlog.com post was written by Patrice Pellerin

Strange wine laws

Karien O'Kennedy — Thu, 21 Jul 2011 23:00:05 +0000

I attended a technical symposium of the South African “Metode Cap Classique” Sparkling wine Association on Wednesday. The first two talks of the day were on CMC (carboxymethyl cellulose) and its use in cold stabilisation. It is derived from a natural product that through a chemical process in a factory achieves its specific functionality and it has been around many industries including the food industry for many years. It is found in all ice-creams as the component keeping it “creamy” instead of becoming icy and is known as food additive E466. In food the legal dose is 10g/kg. In wine the legal dose according to the OIV is 10g/hl. Theoretically one can consume 1 kg of Häagen Dazs in one go (I can) but it is not possible to consume 100L of wine in one go (although many a university student has tried this). The product is not likely to cause any allergic reactions and the lethal CMC dose for a man of 80 kg is 100 000 L of wine. Death by alcohol poisoning will thus come first. HOWEVER, CMC is allowed by the OIV and in most wine producing countries except for the USA. It is considered safe for a three year old to eat it ice-cream but not for an adult to drink it in wine.

Another rather strange rule is that of Natamycin. It is prohibited for use in any wine imported into the European Union. It is an antimycotic (anti-fungus, anti-yeast) which is particularly useful to prevent re-fermentation in the bottle in the case of wines containing a fair amount of residual sugar. There are even speculations that it can be effective against Brett. I am not sure how true this is. The OIV views it as an “antibiotic” which is something that is effective against bacteria and not yeast. It is therefore not permitted for use in wine. The strange thing is that Natamycin is used in most cheese coatings to prevent cheeses from going mouldy. And Europe is a BIG cheese eating nation!

There are various other issues that I could speak my mind on but not without getting fired though. Look out for the pseudonym Poentjie Smit.

Karien O’Kennedy is the editor of New World Winemaker Blog

This NewWorldWinemakerBlog.com post was written by Karien O'Kennedy

Red winemaking at Morgenster

Bernard Mocke — Fri, 15 Jul 2011 09:35:27 +0000

Over the years, South African winemaker, Henry Kotzé, has refined his winemaking mantra to one of minimal interference and maximal expression of variety by means of selecting the best terroir possible. Experience speaks for itself and Henry was appointed winemaker at Morgenster in 2009. Previously, Henry’s oenological skills were honed during his stints at Vergelegen, Boschendal, Neil Ellis and Eikendal (all highly acclaimed South African wineries.) Henry’s focus at Morgenster is on red wine where he works with the classical Bordeaux grape varieties (Cabernet Sauvignon, Cabernet franc, Petit Verdot and Merlot) and Italian grape varieties (Sangiovese and Nebbiolo).

The first vines on the farm were planted in 1994 and the average age of the vineyards is 15 years. The grapes are usually harvested, depending on the fickle weather of course, late February. Average yield is 5.5 tonnes per hectare and juice yield is 700 litres per tonne.

Now, let’s get started with the winemaking section of this blog. This is what Henry had to say: “As the grapes are destemmed and crushed (about 10% is whole bunch pressed), I’ll add an Enartis red wine enzyme for colour extraction. Cold soaking is done for two to four days at less than 10°C. Only one pump-over a day is needed and this is done slowly and gently, to facilitate maximum extraction.” As he says this, he glances longingly at his mud encrusted mountain bike and then back to me. I realise that he’s probably very busy and has not been getting a lot of sleep (the plight of every winemaker!), so I hurry on with my questions. As for the Bordeaux varietals, Henry elaborated about two of his favourite yeasts: “I inoculate Anchor NT 202 and Anchor WE 372 (Oenobrands) at 15°C. NT 202 has always been a stalwart and works well with the wine style that we like to embrace at Morgenster. It is also easy controllable with temperature alterations.

As for WE 372, it is a slower fermenter which really enhances the varietal character of the grapes I am working with. WE 372 makes a particularly powerful contribution towards red berry and fruity aromas when I’m working with Merlot. For my Italian varietals, I use selected Lallemand yeasts. A typical fermentation is done at 26 to 28°C for seven to ten days. I also use a lot of oxygen during fermentations for maximum colour extraction. As an activator I use Laffort Dynastart and Anchor Nutrivin (Oenobrands) and DAP during fermentation.” Henry also formed part of a group of winemakers in South Africa who tried the new Anchor NT 202 Co-Inoculant MLF starter culture (Oenobrands) in 2011.

He says: “I tried the Co-inoculant on a batch Petit Verdot this vintage and was pleasantly surprised with the results, since MLF took only 14 days to complete after AF finished. This usually takes three to five weeks. I usually inoculate all my red wines with Lallemand bacteria, but intend to use the Co-inoculant again next year and in bigger amounts.” Henry explains post-AF as follows: “Extended maceration on skins can last a few days or up to two weeks. After MLF, the wine is racked and three rackings are done during 18 months of barrel ageing. Beta-glucanase (Enartis) is used during ageing.

Optimal filtering would be done with a 1.6 micron candle filter, but where VA is 0.6g/L or higher, I will use a 0.45 micron candle filter.” Henry has his wine bottled during December and January after which it is released three years later. As for the premium Morgenster wines, expect to pay US $69 and US $33 for the Lourensriver Valley range.

Bernard Mocke is a technical Consultant for Anchor Wine Yeast.

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

Vanilla, chocolate or banana?

Edo Heyns — Fri, 01 Jul 2011 10:26:58 +0000

While browsing through the brochures of an alternative oak supplier, I couldn’t help but realise the similarity between buying alternative oak products and buying a milkshake – the flavour profiles for both are “vanilla, coffee and butterscotch”, while if you make Pinotage, I’m pretty certain that you’ll be able to tweak a banana flavour as well! If manipulating the character of wine has become so predictable, one cannot help but wonder how far we are from a stage where winemakers are simply allowed to add the real thing (vanilla, coffee of butterscotch), legally. The surge in the use of wood alternatives could be ascribed to economical restraints as well as relaxed regulatory legislation in Old World producing countries. Barrels are expensive, a hassle to maintain and lose most of their value in the first year or even month of use, while alternatives like staves, chips and all kinds of inserts are cheap and easy – and usually come with a three-step protocol.

To add to this, alternative oaking methods can be viewed as a ‘greener’ practice, since these products are often produced from the off cuts of the staves made for the traditional vessel. While there is a significant drop in global barrel sales, the prominence of wood in wine is increasing, suggesting an obvious increase in the use of alternatives. Ironically the influence of wood in top products is decreasing – with bigger barrels particularly gaining favour – while entry level stuff and conceptual wine brands are often basically oak-driven. Oenological problems or simply bad grapes could easily be masked by an oak overdose, eliminating the need for lower yielding, properly managed vineyards or any significance of terroir.

The question is, where should the line be drawn – How toasted is too toasted? And if stricter measures are employed to regulate when and how oak is utilised, could this be enforced or tested? Perhaps an indication of the type and form of oak used, could become another requirement on labels – along with alcohol, sulphur, animal products and whatever else. The law that naturally regulates wine sales, styles and basically the entire global industry is, however, that of economical supply and demand.

Yes, winemakers play a deciding role in determining stylistic trends and fashions, but eventually the deciding factor is the consumer that buys that bottle of oaky Cabernet, unwooded Chardonnay or banana milkshake.

Edo Heyns is a winemaker, turned wine journalist working for WineLand magazine.

This NewWorldWinemakerBlog.com post was written by Edo Heyns

Sauvignon blanc production – Vergelegen Winery

Bernard Mocke — Thu, 23 Jun 2011 13:43:21 +0000

With quotes like: “Don’t steal, rape, or murder – or make Pinotage” and “We need to separate admiration for the person from awe of the wine. I would much rather that critics dislike me and appreciate my wine than the other way around,” André van Rensburg remains one of South Africa’s most controversial, most successful and most scientific winemakers. André does not focus on awards and neither will I in this introduction, so let’s get on with how he makes Sauvignon blanc!

Harvesting of the 10 to 23 year old blocks took place earlier this year, with most of the grapes being harvested between 3 and 18 February. Harvesting usually starts with the young blocks during the second week of February. From the yield of 5.5 tonnes/hectare, 630 to 678 L of juice is obtained. The high quality of the fruit becomes evident from the fact that a pH above 3.2 is nowhere to be found in any of the settling tanks. Grape processing during crushing is minimised by up to 10% whole bunch pressing. Rapidase Expression (Oenobrands) is added during crushing while Novoclair (Novo) and PVPP is added at the settling tanks. André maintains that skin contact more than two hours is excessive, because ample “skin contact” happens during ripening. Cold settling at 5°C lasts for 48 to 96 hours and some tanks get additional lees rubbing for added aromatic complexity.

According to André, Anchor VIN 7 (Oenobrands) is the ultimate yeast for Sauvignon blanc fermentation. He sometimes supplements his favourite yeast with combinations of QA23 (Lallemand), Anchor Alchemy I and II (Oenobrands) and has even made red wine with VIN 7 in the past! Yeast is added (he does this himself) at 14 to 15°C. Temperature during the lag phase peaks at 17°C, but is then reduced to 12°C for a day after 2°Brix has been converted. After this the temperature is kept between 14 to 16°C and then held at 16°C when the sugar concentration is less than 5°Brix. Fermentation usually completes after 10 to 14 days, with residual sugar less than 2g/L. Nutrient additions are done at 20°Brix, 18°Brix and 15°Brix. He uses Fermaid K (Lallemand) and liquid ammonia (legal in South Africa) as yeast nutrients. Inactivated yeast cells are added during the second day of fermentation. As far as YAN’s go, every tank’s YAN is checked and then increased to 320mg/L. A typical YAN value prior to supplementation is 250mg/L. Ageing on yeast gross lees is done for four to six months and for the reserve, up to eight months. During the first two months, the wine is held at 20°C and stirred weekly for 30 minutes. Beta-glucanase enzyme from Novo is added to the lees after fermentation.

The wine is stabilised four to six months after fermentation, by careful addition of bentonite at a dosage of no more than 50g/hL. Bottling takes place August to September (October for the reserve) and is released for sale directly after bottling. The standard Savvy sells for $17 or £8.99 and the reserve for $25 or £15.

Bernard Mocke is a technical consultant for Anchor Wine Yeast.

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

Sauvignon blanc production – Flagstone winery

Bernard Mocke — Thu, 16 Jun 2011 23:00:52 +0000

Gerhard Swart, Flagstone’s winemaker, is no stranger to awards. His Free Run Sauvignon blanc has consistently received high accolades over the past years and this comes as no surprise considering the care that goes into his Sauvignon blanc.

Let’s take a closer look at how this wine is made. The Sauvignon blanc is harvested from vineyards that are 8 to 12 years old during February and March. Yield is 6 to 8 tonnes/ha. Upon arrival, the grapes are stored overnight in a cold room at 0 to 2°C. The cool grapes are then fed into the crusher under a carbon dioxide blanket. Rapidase Expression (Oenobrands), sulphur dioxide and ascorbic acid are added sequentially at the crusher. Tannin Galacool is added during crushing when Botrytis infection is evident. The crushed grapes and juice is then pumped into a skin contact tank and kept at 2 to 4°C for 18 hours. Free run juice from the skin contact tank is pumped to another tank and skins are pumped to a Velo Evolution Press (the press was designed so that grapes can be pressed in a reductive environment of nitrogen gas). Viniclar (PVPP, Laffort) is added to the free run juice before settling. The press juice is then pumped to another tank. Fining agents such as Polylact (PVPP and casein) and gelatine are added to the press juice. Settling enzyme, Rapidase Vino Super (Oenobrands) is added at the settling tank and this lasts for 2 days at 12 to 13°C.

All Sauvignon blanc fluffy lees is combined and kept at 3 to 5°C. Total sulphur dioxide levels are kept at 35 to 40 ppm. After sheet filtration of the fluffy lees, fermentation is initiated and Turbicell is added to increase the NTU level (sheet filtration decreases this too much and can lead to nutrient deficiencies). A typical minimum NTU level of 80 to 100 is sufficient for Sauvignon blanc ferments.

Gerhard uses the following yeasts for his Sauvignon blanc ferments: Anchor Alchemy I and II (Oenobrands) contributes floral, gooseberry and tropical flavours; Anchor VIN 7 (Oenobrands) makes a big contribution towards tropical aromas; X5 (Laffort) adds boxwood, lychee and passion fruit aromas; QA 23 (Lallemand) makes a contribution similar to the Alchemy yeasts and VL 3 (Laffort) produces a waft of khaki bush. Different yeasts add complexity to the wine. Dynastart (Laffort) is added at yeast rehydration and Nutristart (Laffort) is added when needed. Thiazote (Laffort) is added in 3 stages: after 3°B has been fermented, at 16°B and at 12°B. Inoculation is done at 12 to 13°C and fermentation at 12 to 16°C. Fermentation lasts 2 to 3 weeks after which ageing on gross lees (2 weeks) and fine lees (3 to 4 months) follows. Evolution in wine aroma is monitored during fermentation and ageing by regular tasting and chemical analysis.

The Sauvignon blanc is stabilised at the end of June, bottled at the end of July and released in September. Protein stability is done after final blending, right before bottling. All Sauvignon blanc is treated with bentonite after blending.

The Free Run Sauvignon blanc sells for £10 in the UK.

Bernard Mocke is a Technical Consultant for Anchor Wine Yeast.

This NewWorldWinemakerBlog.com post was written by Bernard Mocke

Wine adulteration 101

Bertus Fourie — Fri, 10 Jun 2011 07:53:45 +0000

The history of the wine trade is filled with stories of wine that has been manipulated, adulterated (substances not related to grapes being added) and even counterfeited. We have grown used to spinning cones and reverse osmosis, electron dialyses and ion exchange, thermoflush and decanting, cmc’s and various cocktails. Do not get me wrong, I also love the science of wine, and I firmly believe you have to have cash to sustain “real winemaking”…profit can only be achieved if costs are reduced and turn over maximised…and if you can use technology to achieve that, why not?

But to add strong acids? To add glycerol? To add flavourants? And call it wine? I can certainly not agree with this, even if legislation does in some cases. Take Mega Purple for example, a food additive that is used to enhance sensory attributes such as color, taste and mouth feel. It is produced by concentrating the teinturier grape Rubired, a cross between Alicante Ganzin and Tinta Cão and has a sugar concentration of 68%. Teinturier grapes is different to vinifera in that it has dark, red juice. Mega Purple is basically a concentrate of sugar and colour, and is added to a wine with insufficient colour to fix the colour to a darker hue, making it more attractive for the buyer. It is common knowledge that a darker, deeper red colour is associated with higher quality, irrespective of the cultivar. It is therefore possible to “change a white wine or Rose into a red wine” by the addition of this magic potion. The downside, however, is that it has its own, unique smell and if you use as little as <1% it may change the aroma/bouquet of the adulterated wine to something less intriguing. Perhaps it is in order to use mega purple in cheaper wines, but as soon as the potion is added to wine, it “homogenise” the complexity of the bouquet significantly. Perhaps the consumer who buys wine in this category does not really care about terroir, nor bouquet, only about price.

If you surf the net to establish how people feel about Mega Purple, you’ll find loads of oenophiliacs giving the wine drinking community a piece of their mind, but no comments from “semi-oenophiliacs”. The question is though: Does someone who buys wine for less than $10 or €3-00 really care? I honestly think they don’t!

From a personal perspective though…I suppose it just does not feel right.

I remember someone saying long ago “it is the complexities of nature that gives personality to our wines…”

Bertus Fourie is a winemaker, turned Enology lecturer and creator of the Barista coffee Pinotage.

This NewWorldWinemakerBlog.com post was written by Bertus Fourie

Judging a book by its cover

Boela Gerber — Thu, 02 Jun 2011 23:00:24 +0000

There has been an interesting debate in the wine industry the last few months, with the influential Platter’s South African Wine Guide in the middle of it. The point of discussion is blind tasting, or to be more accurate: The fact that wines for Platter are not tasted and judged blind, meaning the taster knows what he/she is tasting. One side argues that the judges are biased when assessing the wines because they are influenced by the history, image and marketing activities (or the lack thereof) of a wine estate. The other side argues that wine should be tasted and appreciated in context, taking track record and bottle and vintage variations into account.

People become very animated about the blind tasting of wine, but let’s get a different angle on the topic: It is amazing how much food shopping has changed over the last decade or so. Gone are the days when one had a limited choice of meat and vegetables. Nowadays it is organically grown vegetables and free range meat, where a lot of these options really have merit. But is dolphin-friendly tuna necessarily better than unethically fished tuna and does sustainably grown coffee really taste better than coffee beans from exploited plantations in Africa? Even though the products might taste the same, the holistic product has a feel-good story that adds to the experience.

The problem with blind tasting is that people are not single-sensory beings; blind tasting does not allow for context. I am sure there is a lot to be said for analysing wine unbiased in a clinical laboratory environment to evaluate its intrinsic qualities, but there must be more to wine than evaluating 25 ml of liquid in a glass. Surely 5 generations of winemaking must account for something when walking into the tasting room at Overgaauw, or 325 years of uninterrupted winemaking when opening a bottle of Groot Constantia Shiraz?

I came across an old article in the Washington Post of April 2007 that gives an interesting perspective on this issue:

The article in the Washington Post was about a middle-aged man who played six Bach pieces on a violin for an hour in the Washington DC Metro Station on a cold winter’s morning. During this time, approximately two thousand people went through the station, most on their way to work. A handful of people stopped briefly to listen for a short while and about 20 people gave money as they passed the violinist, adding up to a total of $32. It turned out the violinist was Joshua Bell, one of the finest classical musicians in the world, playing some of the most intricate pieces ever written on a violin worth $3.5 million. Two days before, Joshua Bell sold out a theatre in Boston where the seats averaged $100. Bell’s playing in the metro station was organised by journalist Gene Weingarten from the Washington Post as a social experiment about taste and priorities, to see whether people can recognize beauty out of context.

A statement in this Washington Post article about the Joshua Bell experiment sums up the essence of the wine tasting debate: “What is beauty? Is it a measurable fact (Gottfried Leibniz), or merely an opinion (David Hume), or is it a little of each, coloured by the immediate state of mind of the observer (Immanuel Kant)?”

Boela Gerber is the winemaker of Groot Constantia wine estate in South Africa. This blog was originally published on www.conca.co.za.

This NewWorldWinemakerBlog.com post was written by Boela Gerber