New World Winemaker Blog » Louis Nel

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

pH this, pH that

Louis Nel — Thu, 30 Sep 2010 23:00:25 +0000

We are all taught how important pH is in winemaking. A low pH makes SO₂ perform better by having a larger percentage of molecular SO₂, it makes bentonite settle better, it keeps bad bugs at bay, and generally is something to brag about when you are gathered around a barrel at the end of the day. All this has to do with hydrogen ions, iso-electric points, pH tolerances and lots of other stuff we have long forgotten about since learning about it.

The concept of pH was first described by the Danish chemist Søren Peder Lauritz Sørensen in 1909. The notation given by him was at first p_H, with the subscript H, being derived from hydrogen, but the exact definition of the P is a subject of speculation to this day.

When I was studying the importance of pH was drilled into us, and ‘till this day everybody will tell you how important it is, but besides keeping it as low as possible, tell me, what on earth can you do about it? It is like worrying about your own death.

If we follow good practices like adjusting juice acidity early, adjusting acidity after fermentation and malo, what can you do about pH? Why do we keep analysing something, and wasting money doing it, when the purpose of acidification is so broadly linked to pH and not linear at all. We can just as well stop analysing for it.

I want to ask you how often have you seen lab sheets where people fill in the analysis they have done, and only ask for total acid? If you have the pH, what can you do with it? Be philosophical, brag to your mates about your low pH, worry about it?

When people ask Loftie Ellis (a South African winemaking consultant) what the pH of a wine is, he often answers, “it is enough”. To him the microbial condition of a wine is much more important than the pH.

I have heard of winemakers who do pH adjustments, with legal acids as they should, and then deacidify closer to bottling. This is however an extreme, when you have to take into account that the wine will not win a double gold because of your efforts to fight high pH, but because you have good grapes foremost.

Besides good practice which should always strive to keep the pH of the wine as low as possible, while keeping the affect of acid on taste foremost in mind, you do not need to have the pH of a wine analysed.

This NewWorldWinemakerBlog.com post was written by Louis Nel

Glutathione? What??

Louis Nel — Thu, 23 Sep 2010 23:00:31 +0000

I remember reading and hearing about the next big thing, ascorbic acid when I was just starting out winemaking. It was going to revolutionize white winemaking and everybody who did not know about it was simply out of the loop. Since then, very little has happened, and the practice is not widely employed. I wonder about things that people propagate as fact, simply why it is not used by everyone, it just seems to be so obvious, you would think. Now the next big thing might be gluthathione (GSH). Yes, did I pronounce that correctly?

When you look at all the chemicals in wine that can act as anti-oxidants, SO₂ is not very high up in the chain, and is much less effective relative to other compounds. The series from “worst” to best would be something like, SO₂, ascorbic acid (Vit C), vitamin E, gluthathione (GSH) and then tannin. In white wine there is not a lot of tannin, so the next best thing would be GSH. Many of the flavourful compounds in wines have thiol groups, and when they oxidise, they lose their flavour. This is where GSH can save some flavour, because the source of its power is its thiol groups, which will take a bullet for the flavour compounds.

GSH gets used by yeast during fermentation, so if you want to add this lovely compound you have to add it after two thirds of the fermentation has been completed, because then the yeast will not assimilate it. GSH can be added in the form of yeast derived products.

Recently someone suggested that the use of ascorbic acid can lower the amount of SO₂ needed, but what would be much truer, is that low oxygen pickup can lower the SO₂ needed, since this is actually what is combated by SO₂. When you are evaluating practices and trying to compare two different wineries, you are dealing with different grapes, lots of different micro components, different bottling practices, never mind different ascorbic acid regimes.

Ascorbic acid started as the thing to do, but practical experiments and lots of anecdotal evidence suggest that it is not as powerful as first suggested. The grapes seem to have a much bigger influence than anything else, and ascorbic is not the silver bullet that it was first touted to be. In a few more years we must look back and see what GSH accomplished.

For technical article on glutathione click here.

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

This NewWorldWinemakerBlog.com post was written by Louis Nel

The plastic barrel

Louis Nel — Thu, 09 Sep 2010 23:00:16 +0000

In these times we are all becoming more aware of our impact on the environment and the scarcity of natural resources, and going green is the only way to go. Only 20% of the weight of the barrel is used to improve wine quality while the other 80% is used for structural integrity, so maybe it is time for the “plastic” barrel to make a comeback.

Stanley Kubrick’s 1971 movie “A Clockwork Orange”, got its name from the fact that nothing can be as artificial as a clockwork orange, and similarly more than ten years ago there was a very eco friendly barrel on the market, that I called the plastic barrel. At the time there was nothing I could consider more artificial.

Only the inside of the staves were made from oak, while the outer part was made from cheap wood, and the barrel was covered in oak veneer. The barrel was toasted with infra red light and every second stave had a heating element, so that the barrel could be heated to speed up aging, or to stimulate malolactic fermentation. The barrel could be hooked up to the transformer that supplied the electricity to the elements, and a thermometer would be fitted through the bung to monitor and regulate the temperature inside of the barrel.

Wine only enters the first 5mm or so of a barrel and the rest of the oak is wasted, so conserving this natural resource could be highly beneficial. Besides that only 4% of the wood of an oak tree is good enough to be used for making barrels, so you will be saving a lot of trees, while wood that is more plentiful can be used for the structural integrity of the barrel.

At the time I was part of a huge contingent that thought such a barrel is the biggest load of fakery around, but if it lived on we could have had a lot more manufacturers, who could have improved on the concept.

When using staves, a much larger percentage of the oak tree can be used for making staves and the staves have a smaller carbon footprint when transported, because you are not transporting so much French or American air. All the oak is used and none is wasted to keep a barrel from collapsing.

Maybe it is time to revisit the plastic barrel, and look at ways where this “artificial” product can, like screwcaps, low carbon footprint plastic bottles, and staves be used to protect natural resources and hopefully save the planet.

This NewWorldWinemakerBlog.com post was written by Louis Nel

The devil you know

Louis Nel — Thu, 26 Aug 2010 23:00:23 +0000

We are taught the benefits of protein stabilization of wines, and accept it as fact. We believe because we are told to. Then sometimes along our wine journey, a suspicion creeps in, we have never seen this “haze” formed by protein instability, is this just another Father Christmas story, one that cannot be true? Like any religion, winemaking has stages, and one sometimes does some church hopping to find the right way of doing things.

When I was a young bright-eyed winemaker, straight out of university, I got excited whenever I met a well-known winemaker. They were my rock stars, and I wanted to be one. What makes them so special, what can I learn, what wisdom can I glean from their fertile minds? I would seek the answer, and go to the mountain and climb it, to find my guru.

At this time I met some of the most decadent rock stars, who told me that adding too much bentonite is just plain evil. It is a conspiracy of the bentonite magnates, who have underground meetings and want to sell tons of the stuff to the masses (this bit I just made up). Bentonite just strips wine, and should be used in very conservative amounts. The recipe the gods gave me was, whatever the lab says, add half of it. If the bentonite requirement was 80g/hℓ, add only 40g/hℓ. I came down from the mountain, and applied this wisdom for a very short while, because I finally found the haze that my lecturers taught me about. Luckily it was a very small run, and did not mean the financial ruin of my boss, but from then on I was a much safer winemaker. I was cured from following gurus for a long time.

There are lots of things that we are taught that we just accept as fact. Most of them are too dangerous to try and disprove, so we might never know the truth. At the other end of the spectrum there are people who get away with bad winemaking practices, because they have a cool cellar, have wine that is not prone to pinking, have a naturally low bacteria count in their wines, have naturally low Brett counts and other blessings. The impact of moving to another cellar where things are not the same as at home, can, however, be disillusioning.

Count your blessings, because you do not know, what it is you don’t know.

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

This NewWorldWinemakerBlog.com post was written by Louis Nel

Cold stabilisation now

Louis Nel — Thu, 19 Aug 2010 23:00:08 +0000

Cold stabilisation of wine is one of those things that is very difficult to determine. When is a wine stable, and under which circumstances is it stable? The method used to determine the level of cold stabilisation will determine that. At one time the water bath method using electrical conductivity as a measure was popular, but it actually only determined the level of cold stabilisation at 0°C. The minus four degrees centigrade freezer test, determined the level of stability that the wine will have under those circumstances, and not necessarily for a longer time, and at a lower temperature.

With all these philosophical headaches to contend with, the only proper way of stabilisation was to keep the wine cold for a very long time, or to seed it with crystals at a very low temperature. The effect was that the wine was often exposed to oxygen at very low temperatures where it can dissolve very easily, but it would only react at higher temperatures. Apart from these negatives the energy usage, cost, lowered total acidity and loss of carbon dioxide gas was a worry. Often wine had to be sparged with nitrogen inline after stabilisation to push out oxygen, while removing CO2, possibly flavour, and the nitrogen itself dissolving at low temperatures, foaming when the wine is mixed at a higher temperature. The biggest drawback in future will be the energy used during this process. After this long list of negatives, one would think that there would have been alternatives by now. Well there are, sort of.

Being an avant garde winemaker in my youth, I dabbled with mannoproteins even before they hit the shelves. Here was a product that would keep all the valuable attributes of the wine, without any of the negatives of cold stabilisation. The only drawback was that it only worked so-so. The product was too dodgy to use on big Tesco orders, and the amount of comebacks was always just below the threshold for concern, but only just. At bottling time I would often find that the mannoproteins would form a slimy layer on the filter sheets, and sometimes even block a filter. This meant that some of the proteins where being filtered out. I tried to compensate for this by adding the mannoproteins during bulk filtration, thereby filtering and dosing it at the same time, but I never knew whether the difference was just in my head. All said, Australia shunned the product until other countries stopped experimenting with it.

Another alternative for stabilisation is electrodialysis. This procedure involves a membrane that, at room temperature, removes destabilizing ions, potassium, calcium, tartrate salts using quite a low current. The energy usage is very low, but the capital requirement is quite high. Many people are touting this technology as the next big thing, because it does not seem to lower the TA significantly, and also (apparently) seems to improve the sensory aspects of wine.

The latest technology that is making my tail wag is the use of CMC. CMC is carboxymethylcellulose, and it was recently legalised by the OIV. CMC is used in food as a viscosity modifier and emulsion stabilizer. CMC works the same way as mannoproteins inhibiting crystal growth, and is added to wine just before bottling. The only negative aspect of CMC is that it is not a natural product, and if not used, has a relatively short shelf-life. The OIV specified that CMC’s used for winemaking must be of wood origin, so that would help a bit for the conscience.

I hope CMC is what it is cooked up to be, because it could be a wonderful breakthrough.

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

This NewWorldWinemakerBlog.com post was written by Louis Nel

Turning water into wine

Louis Nel — Fri, 13 Aug 2010 09:27:13 +0000

There is an old story doing the rounds about one of the pioneers of the South African wine industry. The story, that will never be verified, says that the wine that always stood head and shoulders above that of its neighbour’s, was made in the early eighties by picking the grapes extremely ripe and then adding water. The fruit intensity and softness of the wine’s tannins were unknown at the time, and the wine was very popular.

In the USA the humorously named practice of humidification and more officially named, rehydration of grapes is quite legal. The California Wine Institute sought official approval from the authorities for adding enough water, to replace that which was lost from grapes through field dehydration, and it was granted. The exact amount of water that can be added is not stated outright, but it could be very high. Water is also allowed in California to bring the sugar down to a level that will prevent stuck fermentation.

In Australia a maximum legal amount of 70ml of water per liter of wine may be added, but only during the normal course of winemaking, and not necessarily for the dilution of wine or juice. There are rumours that the practice of the addition of water derived from reverse osmosis is also used from time to time, since it is derived from grapes anyway.

All the practices of water addition that I mention here are to improve the wine and not to dilute it. It is there to prevent stuck fermentations and to improve the flavour and tannin structure of the wine while not having ridiculously high sugar levels.

South African law will soon be catching up, and a recent notice from Wine and Spirit Board stated that, “Pending further directions from the administering officer of the Liquor Products Act and the Wine and Spirit Board, water will be able to be added to certified wine for the correction of moisture losses in grapes. We will let you have above-mentioned directions as soon as they become available.”

This NewWorldWinemakerBlog.com post was written by Louis Nel

Cabernet Franc of my dreams

Louis Nel — Thu, 22 Jul 2010 23:00:24 +0000

The other night I had a most amazing dream, dreaming of a Cabernet Franc that just blew me away. There are a few local (South Africa) examples that blow your socks off, but then there are a dozen ugly Betties. What makes this variety so fickle, with a Jekyll and Hyde personality that sometimes makes you smile, and other times cringe?

Cabernet Franc in its best form is the reason Cheval blanc is amazing, and it is one of the parents of Cabernet Sauvignon. From noble descent yes, but where do the white trash, green and yucky traits come from?

Cabernet Franc has two weaknesses in its armor and one being its susceptibility to virus infection. Cabernet Franc has often been used as an indicator plant to test for the presence of virus, and this leads to vineyards that once performed amazingly in their youth, to become amazingly bad by the time they reach their teens. One vineyard I can remember was a five star winner in Wine Magazine in its youth, and when it was about 15 years old it was one of the worst blocks on the farm. By then another Cabernet Franc vineyard that was still young became the crown prince of this beautiful piece of terroir.

The other chink in its armor is its tendency to produce a huge amount of green flavours. Once green flavours enter a cellar, it will survive a nuclear attack with only the cockroaches to keep it company. It is just about impossible to get rid of. The best way to prevent greenness is to follow vineyard practices that prevent green flavours. One of the few analysis that seems to correlate with greenness is malic acid and this is also correlated with very dense canopies. There is actually a direct relationship between the amount of leave layers over a bunch and green flavours. The simplest way to prevent greenness in the cellar is to error on the high side with sugar ripeness when picking, to prevent dense canopies, and to expose of bunches as much as possible.

To say that you can do nothing in the cellar to combat greenness is a bit of a stretch, but for all practical purposes it is true. Many ways have been described to bring down greenness in the cellar, but the exact impact you will have to determine yourself. Besides these methods, that I will describe in another post some time, the only treatment that is suppose to help is basically cooking the wine, which is simply not on.

Interesting enough, the Asian Lady Beetle (Ladybug) that has caused lots of havoc overseas, produces exactly the green flavours in wine that we want to avoid. Hopefully research to combat the flavour induced by the ladybugs, might just give us the answer to fixing green flavours in wine.

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

This NewWorldWinemakerBlog.com post was written by Louis Nel

Glycerol this, glycerol that

Louis Nel — Thu, 08 Jul 2010 23:00:22 +0000

Karien’s comments on the hype that was made about glycerol, makes me nostalgic. Everybody was caught in the frenzy to find ways to increase glycerol in wines, and people went to extremes to achieve their goal.

Glycerol is one of the base chemicals used to make dynamite, and the commercial production of glycerol involves yeast fermentation, where SO₂is added constantly. To protect itself from the SO₂, yeast produces glycerol. Winemakers tried to simulate this effect by stressing the yeast during fermentation. Treatments included adding small amount of SO₂constantly during fermentation, adding unfermented juice to wine (osmotic shock) and stressing the yeast by cooling it suddenly. Many winemakers (and some of the best) practised fermentation practices where the must was cooled to 10°C, allowed to rise to 15°, cooled quickly to 10°C, allowed to warm etc, to increase the amount of glycerol in the wine.

All these techniques probably resulted in an increase in the glycerol concentration, but had no effect on quality resulting from the glycerol.

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

This NewWorldWinemakerBlog.com post was written by Louis Nel

Wine au Natural – warts and all

Louis Nel — Fri, 18 Jun 2010 06:00:48 +0000

There is a movement in winemaking that strives to make “natural wines”. These wines, sometimes called “real wines”, are wines that contain nothing but grape juice. In its purest form no additives whatsoever are added to the juice and the wine often does not contain any SO₂. This leads to a wine that is as pure as nature could have intended it, and sometimes quite far from what often is considered ideal.

The wine will have no protection against oxidation, and could sometimes turn brown within hours of opening. The acid might be way too low, which might let other components such as tannin, alcohol and fullness suffer. But the purpose of creating a wine where nothing was added, and the elixir of life being as natural could make it, is achieved. In the fashion world there also seems to be a movement away from perfection, with more normal sized women, with more natural dimensions and figures making a comeback.

“Winemakers” of this natural wine would sometimes let you know that it is even more difficult making natural wine, than normal wine. Fermentations are followed under the microscope, and the timing of picking is very critical. Organic winemakers have been using similar techniques, with mixed success. The Holy Grail seems to be a balance between natural techniques and modern winemaking.

Chris Anderson wrote an article (and lately a book) in Wired magazine in 2004, on the phenomenon known as the “long tail”. Chris postulates that in a market where there is an extreme amount of choice, about 20% of sales will be made out of a very small amount of products, while the other 80% of the total buying power is spread over a huge amount of products. This long tail can be extremely profitable, because it means that there is a market for a very large amount of small products. In a video store about 20% of the rentals will be made out of a very small amount of titles, while the presence of a large assortment of other titles will take care of the rest.

Making natural wine will be somebody’s ticket to success in the long tail.

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

This NewWorldWinemakerBlog.com post was written by Louis Nel

I am winemaker

Louis Nel — Fri, 28 May 2010 06:00:50 +0000

There is now a very secret winery in the Winelands that nobody is suppose to know about, where no eye is suppose to roam, and of which no word may be spoken. Could it be that this winery has discovered the hidden secret to winemaking that nobody else have been able to find, and that this group of people have something that can be so powerful, that the effect will be so amazing that their wine quality will far surpass that of icon wines?

Every generation of winemakers think they will discover the secret to winemaking. They think that their understanding and insight far surpass that of every other generation. Every young generation also think that they discover the art of making love for the first time.

Winemakers should get better with years and experience, but sometimes ten years experience of only one situation, is equal to only one year repeated ten times. To grow one has to constantly challenge yourself, otherwise you should just retire.

Every winemaker has a certain pride in what he does, but to me “pride”, is often not remembered as one of the seven deadly sins. This emotion in my book should just not be good practice.

Good stock and commodity traders are always nimble and quick, and have no hesitation about changing their minds about the direction of the market. If they bet on the market going down, and the market goes up, they change the direction they are betting on, without sticking to their original believe or arguing with the market. Pride should always take a backseat to reality, because you cannot argue with reality. People however have a different perception of reality, which makes this argument a bit tough.

Winemakers offended about new ways of thinking, or techniques that challenge their traditional doctrine, should do some soul searching. Are they going to stick to their self imposed religion of winemaking, or are they going to test everything, keep the good and discard the bad?

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

This NewWorldWinemakerBlog.com post was written by Louis Nel

Mister/Sister, are you good in the Cellar?

Louis Nel — Fri, 14 May 2010 06:00:50 +0000

What makes a winemaker good, and others not? Is it nature or nurture? Many years of winemaking experience have humbled me to the point where I have no illusions regarding the origin of wine quality, and where I have a much better grasp on the influence I have on a wine. My guess would be that if you have stunning grapes, you are 80% there, with the winemaker being able to add another 20% to the total quality that is locked into the grapes.

On the other end of the scale, if you have very mediocre grapes, a winemaker will be able to add, and manipulate the quality of the resulting wine to add maybe 80% to the quality of the final wine. My theory could be illustrated as follows.

As humans our evolutionary process has tried to equip us with survival skills, that amongst others include tools to learn from the environment, but inadvertently, we see patterns and relationships where there are none. This condition known as Apohenia, make us correlate, totally unrelated criteria.

A common bad correlation would be to say that good winemakers inhabit some regions more than others. Good grapes do occur in certain regions more than others, which might be more correct. Some people think that men make better winemakers than woman, but then how many woman winemakers are there, how many chances have they received?

One certain bad correlation often made in interviews is that an extrovert personality correlates with winemaking skills. The personality profile for the ideal technical winemaker, would normally exclude this profile. People would often prefer to vote for somebody in an election because he is a good speaker, or looks the part, rather than on merit. If my theory is correct, and you have stunning grapes, you do not need a very good winemaker, you are 80% there anyway.

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

This NewWorldWinemakerBlog.com post was written by Louis Nel

You want me to put it where?

Louis Nel — Fri, 30 Apr 2010 06:00:02 +0000

I am not a non-interventionist winemaker, simply because I do not trust fate at the wheel of my winemaking career.

We are often warned of the danger of processed food to our health, but what constitutes processed food? The common definition of processed food is any food that is handled through a process. Basically slaughtering and animal to get meat, or picking or handling food constitutes a process that leads to processed food. William S. Burrough’s name of his novel “Naked Lunch” refers to the fact that food is never as naked, as it is at the end of a fork. But the purest would argue that often food is not “raw” anymore, but “dead” by the time it is naked at the end of your fork. Is wine natural by the time it is in your glass? My current winemaking philosophy is that I do not want add anything to wine that will take anything away from it.

Basically I do not want to add fining agents, as far as possible, while at the same time I would consider tannin additions, acid and similar additions that will add something to the wine and make it better, more favourably. Dominique Delteil always warned of the effect yeast has on a wine’s colour, because the proteins in the cell wall would bind tannins that are bound to colour, and thereby reduce he colour of the wine. The real world effect of yeast reducing colour is difficult to fathom, but the possibility and effect exists.

One should therefore in theory either use wild yeasts (very small amount of yeast) or yeast that you know will do the job of fermentation well, so you would not need to re-inoculate and thereby fine some colour out with the new yeast cells. One of my pet peeves is the economical use of the truth by chemical and additive suppliers. Their graphs show the speed and efficiency clearly visible on their graph at presentations. They never ever show the correlation of their product with quality.

Does speed of malolactic fermentation correlate with quality? Was their microbial experiment that they used to get the data from, representative of the whole industry? When I buy malolactic bacteria, imagine my reaction, when together with my expensive packet of bugs, I am given a bag of yeast hulls, to help along the kinetics of the malolactic bacteria, and to help fine the colour out of my wine.

What??

Wine is a complex soup of chemicals, with interactions and kinetics quite impossible for any human brain to fathom exactly. Just because there is potassium in potassium metabisulphate, will it affect the pH of my wine significantly? Will my wine treatment improve the quality of the wine, or will throwing salt over my right shoulder have the same effect? I have said it many times, may we never stop learning, and wondering what is around the next corner.

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

This NewWorldWinemakerBlog.com post was written by Louis Nel