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.

“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 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.

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.