New World Winemaker Blog

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.

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.

“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.

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.