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:
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.


by Marcia
04 Jan 2012 at 10:53
John -
The engineer in the family (not moi) is curious about what stressed yeast looks like or behaves differently from yeast doing its usual bit in fermentation. Is it something you can see happening at the time of fermentation?
Thanks,
Marcia
by John M. Kelly
04 Jan 2012 at 15:40
Hi Marcia – never seen stressed yeast look all that different under the microscope in an ordinary (if stressed) ferment, though they do appear different under strong osmotic shock—really high sugar or really high alcohol, (or salt, or any solute other than water). In extreme cases of stress a large fraction of them will appear dead when treated with vital stain. When a ferment is stressed it may get sluggish, i.e the rate of sugar depletion will decrease. In the winery I can usually tell when a ferment is not going well by its aroma—not just eggy but also a subtle, indescribable funk. I don’t even do it consciously any more; when I open the door in the morning I can tell if something is going wrong almost instantly, and then identify the offending tank when I start punchdowns. Thankful that it doesn’t happen very often. BTW aside from high sugar/high alcohol, temperature is a stressor too. Classic is an overheated ferment but among the worst I ever smelled have been ferments where a tank jacket solenoid failed open, chilling the must rapidly in the middle of fermentation. Competition with bacteria can also cause yeast to stress.
by Jan
10 Jan 2012 at 09:24
I completely agree that people are too stuck on the idea of wine over 14% being “not good”. It’s a ridiculous made up number that people do get too hung up on.
However, I do find your chemistry a little bewildering. It doesn’t seem to me that “dry barrel aging” would have anything to do with alcohol levels increasing unless there are additional yeasts present. By your explanation, the laws of thermodynamics would say the water evaporating from the barrel would increase the concentration of alcohol. However, alcohol evaporates at a much faster rate than water and there is never alcohol in the atmosphere.
I agree with you combatting the idea that over 14% alcohol wine is bad but doing it with misinformation leaves other people in the industry cleaning up after the chemistry tales. I do still love your wine regardless of the alcohol levels and other people will too!
by John M. Kelly
10 Jan 2012 at 10:18
Hi Jan: not just yeast but sugar too, by your lights. But no, there is no fermentation activity in the barrels.
Alcohol increases in barrel to some degree during aging. This is an observation. It is a fact, and I’m not the first or only winemaker to make this observation. Ask around; if people are honest you will hear stories of labels being printed 6 months before bottling that have alcohol levels lower than the final bottled blend actually measures. It’s a real problem when the wine jumps a tax class—it happens.
My dry cellar idea is an attempt to explain the observed reality—it constitutes a testable hypothesis. I have experience working with materials that are semi-permeable barriers. Before I started graduate work I managed a research project involving gas separation by spun hollow fibers of cellulose triacetate (same material used in reverse osmosis, some other molecular sieves, Saran wrap, etc.). These fibers permeated CO2 and H2S very efficiently but were impermeable to hydrocarbon alkanes (methane, ethane, propane, etc.). If you care to look it up you will find there are many processes that exploit semi-permeable barriers.
My hypothesis is that the barrel is a semi-permeable barrier and that as such the dominant process is not evaporation (where the relative rates of change of the concentrations of different components in a mixture are controlled by their relative vapor pressures at any particular temperature). I hypothesize that the presence of the barrier imposes conditions where the differential in the concentrations of the different components inside and outside the barrier is the dominant factor controlling the relative rates of change.
I’ll double down, and speculate that the barrel is more permeable to water and less permeable to ethanol. This would suggest a 2nd-order factor controlling the relative rates of change in concentration, one where the water crosses the barrier slightly faster than the ethanol. Again, this is a testable hypothesis.
by Bob
10 Jan 2012 at 09:53
Thanks for the explanation. I’ve heard similar complaints from winemakers when consumers pay too much attention to alc levels.
But I will say I’m one of them now.
Pretty much everything I buy I’ve tried first in the tasting room. I’ve bought several labeled with what I’d consider high alcohol percentages. The vast majority of the time these wines just aren’t very good whether I had them a few weeks or a few years later. I don’t know if it’s a poor shelf life, or I’m just taken by the easy fruit flavors when tasting, or they’re just bad food matches. I’ve dumped too many expensive wines down the drain because these monsters are more like a Dr. Pepper with a shot of tequila than a table wine.
I buy according to price, variety, sometimes other factors, and now by alcohol level. I’ve learned from my mistake.
by John M. Kelly
10 Jan 2012 at 10:36
Hi Bob: I’m with you in spirit, up to a point. I have no love at all for “cocktail wines” whether they have high alcohol or not. I consider wines made from very high sugar grapes and aged in very high fractions of new oak to have “cocktail wine” attributes, even if the alcohol level has been lowered by RO or spinning cone. These wines are fatiguing to drink, and generally don’t complement my appreciation for food.
But high alcohol alone will never be my a priori reason to reject a wine. If it were, I’d never drink Port, or Madiera (right?)—and I love some examples of those wines. I will give a wine a shot even if the winemaker tells me they picked at 29° Brix, raised the wine in two changes of 100% new Darnajou barrels, and got 98+ points from so-and-so. I won’t expect to like such a wine, but I will try it, and take joy if it in fact turns out to be something drinkable. It has happened.
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[...] 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 [...]
by Edward Lohmann
31 Jan 2012 at 07:36
Interesting observation, Same questions I sometimes encounter in the tasting room…..usually from some know-it-all. Cheers
My blog: thegrumpynortonian (almost all about the Norton wine)
by John M. Kelly
31 Jan 2012 at 11:36
Hi Edward: Sure, I have no problem promoting your blog here. More and better wines made from Norton and more consumer awareness of them is a laudable goal, in my opinion. Best of luck.