Ageworthiness and alcohol level

I was asked whether there’s any truth to the assertion that high alcohol wines don’t age very well. To summarize what we know about ageworthiness, we should recognize two distinct realms where observations have been made. One is that, on the whole, wines with high alcohol tend to have higher overall ripeness. There is much experience and scientific understanding to verify that these wines age poorly. But this tendency is not universal, because brix and ripeness are only loosely connected. Secondly, we have a small body of experience and research which suggests that alcohol itself somewhat hastens ageing in otherwise identical wines.

A key distinction must be made between a wine’s alcohol level and the state of ripeness of the grapes, which leads to the compositional status of the resulting wine. Alcohol level is closely related to the brix at harvest unless the wine has been adjusted: add any additional alcohol from chaptalization or fortification, minus any alcohol which may have been removed by the various existing mechanical processes such as reverse osmosis or spinning cone.

Fruit ripeness is only loosely related to the grape’s sugar content. Depending on the climate in which grapes are grown, and particularly the weather at harvest, grapes may reach the same state of compositional ripeness (color, flavor, tannin status) at anywhere from 20 to 30 degrees brix. The low numbers are common in France, and in fact in many parts of Germany, 20 brix is considered late harvest for riesling. In California, which lacks autumnal rainfall, riesling often doesn’t reach the same degree of ripeness until the high 20’s, and cabernet is typically also picked between 25 and 27 brix. But in a cool year like 1999 or 2005, much California fruit got overripe by hanging too long while winemakers were waiting for these numbers.

Overripe red wines lack fresh aromas, have low reductive strength, develop pruney aromas and fail to age well. In technical terms, the degree of oxidative polymerization of the tannins has proceeded on the vine to an excessive extent. It might be said that the wine has run down the chemical battery it normally uses to protect itself from oxygen during ageing in barrel and in bottle and to defend itself from oxygen-loving microbes like Acetobacter, or vinegar bacteria. High ripeness also tends to be associated with high pH, which is the “gas pedal” of ageing, and controls the rate of oxidation of many wine constituents. Such “over the hill” wines tend to brown early and their tannins dry out — that is, they become grainy and move from the top of the tongue to under the tongue and into the cheeks, giving a dirty impression which obscures flavor perception. The tannins have essentially curdled, and just like a botched bearnaise sauce, they fail to integrate aromas. As a consequence these wines show, along with oxidative notes of caramel and prune, also disjointed aromas of oak, vegetal notes and microbial smells, which then protrude in the nose in unpleasant disarray.

On the other hand, sometimes grapes achieve very high brix without these problems. A case in point is the 1999 CSU Fresno Syrah in our study, which came in on September 17th at 31 brix, but possessed fresh blueberry aromas and fine, firm tannin, and is still drinking quite well today. So high alcohol per se does not necessarily indicate overripeness. This wine was, however, quite hot on the palate, and the high level of alcohol caused a bitterness in the finish and also exacerbated the astringency of the tannins. When we adjusted the alcohol down to the normal range, these imbalances disappeared, and the wine did well in competitions and aged well.

Not so the unadjusted 18% wine, which more rapidly developed raisiny notes, browning, and oxidation. A dozen or so trials over the years have shown us that high alcohol wines develop differently than their counterparts in which we have reduced the alcohol, wines with exactly the same composition of color, flavor and tannin. We often see zinfandels developing raisiny notes more rapidly at higher alcohol, for example.

We don’t know why this is happening. A possible explanation may stem from the fact that at higher alcohol, wine has a greatly diminished dialectic constant — the driving force of water to “herd” phenolics into the colloids. These tiny tarry bead-like gobs hold most of the color and tannin in red wine. They also provide a protective zone for many aromatic compounds to insinuate themselves inside. I can only speculate that the decreased stability of these colloids at higher alcohol exposes these hidden aromatics to oxidative attack.

Concerning alcohol “sweet spots”

Mr. Smith,

Thank you very much for your thought-provoking response. I did spend time looking through the Vinovation website, and I also picked up the recent _The Science of Wine_ by Jamie Goode to get some medium-level descriptions of the processes.

I'm just beginning the research for this article, so I'm not yet on deadline. I'd be happy to set up a time to chat when you get back from South Africa. I live in Oakland, so I can easily arrange to come up to Vinovation to talk to you. 

 Would it be possible to attend a sweet spot tasting? I realize your  clients consider this a sensitive area, and I'm happy to sign nondisclosure/confidentiality agreements if they're nervous about being fingered in the press. I just want to get a sense of what the  tasting process is like. 

 I assume each wine has a different set of sweet spots? 

 How different do the wines taste? Or to put it another way, could you  spot a Vinovation client in a blind tasting? Maybe because of the  characteristics of the structure? 

 Do you have a sense of how well Vinovation wines age? How gentle is  the "sweet spot" process? 

 I'm trying to grasp how other wines fare without your consulting. You  mentioned chaptalization, but do European wine makers just add a  known quantity of sugar that always brings them to the "right" alcohol  based on yeasts and brix (or Baume, I guess). And if the "right"  alcohol varies from wine to wine, how do they know how much to add.  And what do the CA wineries that aren't your clients do? 

 In other words, good wines do come out of France without adding sugar  to the grape must, and you pointed out that few of the vineyards can  generate "natural miracles." So what explains the discrepancy? 

 Can you point me to the research about brix vs. phenolic maturity? 

As always, thanks for your time and thoughts.

David

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Dear David:

Thank you for your emailed queries.  Thank you also for the time you have obviously invested in thinking over the matters we discussed.

You would be welcome to attend a sweet spot trial at any time.  Perhaps the time coordination logistics and the confidentiality aspect would best be addressed by your attending some trials I need to do on my own wines: I have a pinot noir, a cabernet and a sur lies chenin blanc coming up which I'll need to fine-tune in the last half of May.  Let me know two or three days which might work for you and I'll pick one to schedule for.

I don't actually think this whole area is a terribly big deal. All wines require fine-tuning just as all other cooking requires the chef, just at the end, to "adjust seasoning."  There are hundreds of ways to do this.  Even in a single vineyard, single varietal situation, a good winemaker will divide the harvest into sub-lots which are treated differently — different maturities, different yeasts, different oak — just to provide blending options later on.  Alcohol adjustment is just another example.  Scientific enologists often don't take this approach, preferring to adhere to their theoretical notions of purity of varietal character, minimum manipulation and so forth rather than to roll up sleeves and apply technique to an harmonious and focused product.  This inattention is evident at the preponderance today of technically unflawed but utterly uninteresting wines on the market.

I don't mean to besmirch the pursuit of scientific investigation.  But I do question whether we've really gotten anywhere except to acquire bad habits in our thinking.  Science today seems to think itself arrived at certainty rather than engaged in inquiry.  In studies of the nature of wine it reveals its inquiry to be barely its infancy, and largely headed in the wrong direction.  Sweet spotting exposes two of its key paradigms as demonstrably bankrupt. 

The first is the application of the dilute aqueous model, in particular the linear correlation of the concentration in "solution" of wine constituents to "drivers" of sensory aroma and taste intensity such as fruitiness and sweetness.  As you'll see, it just doesn't work like that.  The analogy to musical tuning as opposed to dissonant noise comes closer to the mark. 

The second is the stress on sensory acuity — supertasters, differing salivary rates, bitterness thresholds, specific anosmic profiles — as proof that wines are perceived differently by different people.  But   everybody agrees where the sweet spots are and also how they characterize themselves.  Moreover, in between them there is general agreement that the wines are disharmonious — more astringent, less sweet, less focused.  We really have no idea what's going on, but these effects are clear.

The strong agreement on what's harmonious and what's dissonant is good news for winemakers.  Like a musician needs to believe that the emotional communication power of music is universal, the winemaker needs to know that tuned up is tuned up for everybody.  Like any other cooks, winemakers need to adjust the sauce with confidence.

Alcohol sweet spotting has fascinating special value as a probe into wine's true nature simply because it is so simple to adjust and because it has little flavor of its own.  Its relative purity allows it to demonstrate with greater clarity than other blending techniques the nonlinearity and universality of wine balancing.  Conversely, from an artistic standpoint, it is comparatively  mundane.

When we do a sweet spot trial, we reduce the original wine (via our recombinatory reverse osmosis permeate distillation process) to somewhere below where we think we want to end up.  Then we blend the original wine in, or we bump the alcohol back up by adding back high proof alcohol, either way laying out fifteen or twenty wines which are different only in their alcohol content and separated by 0.1% alcohol.  For example, we might take a 15.0% chardonnay and look at the range of 12.5% to 14.5%, 21 wines lined up: 12.5, 12.6, 12.7…14.4, 14.5%. You'd think the wines would just gradually get better, then worse.  That never happens.  There are marked differences in "harmoniousness."  You see maybe one wine in siz that is focused.  The rest  are astringent and unbalanced.  Kind of like the unfocused, defect-free wines you usually see on the market.  The differences are pretty obvious.

Could an expert pick out such wines?  Well, perhaps on occasion a zinfandel possessing ripe, round tannins or a viognier with well-developed honeysuckle aromas but without the expected hotness might lead one to speculate that the technique had been employed.

As for its gentleness, It actually involves very little processing and by any standard of wine treatment, that is if one were to compare the effect of, say, pad filtration, cold stabilization, or bentonite or egg white fining, it is certainly less deleterious to flavor than these normal and accepted treatments which attract less attention.

There doesn't seem to be any way to predict where the sweet spot will show up. 

On the other hand, we do have names for the styles we often see. We talk about the "jammy, in-yo-face CaliforniaZin" vs the "SuperTuscan" sytle the same wine can exhibit at lower alcohol: less forward fruit but more refinement and length.  In Chardonnay we often see the "California Montrachet," the "Mersault style" and the "Faux Chablis style."

It is also predictable that high alcohol wines will be hot, bitter, and low in fruity aromas, while low alcohol wines tend to be thin, salty, and possessing what we call acid-based astringency.  And we usually see these same characteristics in the wines one tenth of a percent above and below the sweet spots.

Your instinct about chaptalization in Europe is, I think, correct.  Proper harmonious balance isn't normally achieved.  That's OK, though.  They just have to find another means to fine tune the wine.

For a great reference on the non-connectedness of brix/baume/oechle/sugar content vs true maturity, get:

Australian Journal of Grape and Wine Research, Vol 6, No. 2 Proceedings of Symposium on Reproductive Biology in Grapevines.  This is sort of my bible on this topic. 

Relating to ageing, empirically we often see that the same wine aged at different alcohols ages differently. Experiments on Zinfandel by Carole Shelton and at Murphy Goode on Merlot showed that higher alcohol wines develop more raisiny aromas.  We don't know why.  There may be a relation to the considerable suppression of dialectic constant at higher alcohol, but the effects are larger than one would expect from a shift to 14.5% to 13.5% as in Carole's trials.  Colloids are a lot less stable at higher alcohol, and this may also relate.

Regarding MOx, it is clear from large numbers of trials that wines properly structured with oxygen have considerably more longevity than their conventionally made counterparts, which tend to dry out, precipitate structure, brown, and push aromas of veggies, oak and Brett while the MOx'd counterparts are still holding together well.

Hope this helps.  Let me know.

Best regards,

Clark

PS  I'm still looking around for that old Wine and Food Companion on pairing wine and oysters — must be buried in the garage somewhere, but I'll keep you in mind to receive a copy whenever it gets unearthed.