Want Some Wine With That Booze? (The “Parker Effect” And Rising CA Wine Alcohol Levels)

Vinted on May 24, 2011 binned in California wine, commentary, wine news, winemaking

The Center for Wine Economics released a report of a recent study on the sugar levels of wine grapes in California, titled “Too Much of a Good Thing?  Causes and Consequences of Increases in Sugar Content of California Wine Grapes.”  Not sure how new this news is, but it was new to me so I’m yappin’ about it!

While that title of the report doesn’t sound particularly fascinating, the report’s conclusions are – if you’re a wine geek, that is, and if you’re a fan of California fine wine and have ever wondered why alcohol levels seem to be kind of high in the premium vino coming out of that state.  According to the report, it’s not just your imagination – wine grapes in CA have indeed been getting riper over the last twenty years, which translates into higher booze levels, with white grapes bearing the brunt of the increase:

“The data show that the average alcohol percentage increased by 0.30 percent, with a larger increase for white wine (0.38 percent) than for red wine (0.25 percent).  This increase in alcohol percentage is consistent with an increase in the sugar content of the grapes used to make that wine of 0.55 degrees Brix, on average.”

That sugar measurement might look small, but according to the report it’s a “substantial” increase, and it’s that rise in sugar levels that is making CA wines a bit more… busty than they’ve been in the past (I imagine if you were used to drinking CA wine from 20 years ago, drank too much, passed out and pulled a Rip Van Winkle, upon waking up in 2011 you’d be forgiven for thinking that during your extended slumber your fave CA Cab had undergone the vinous equivalent of a boob job).  What this study does that is so fascinating is this: it puts data and critical thinking behind something that many CA wine drinkers may have already suspected… CA fine wines are getting boozier, and it might be the result of the fine wine market

Now, we’ve all heard of global warming, right (if not, please remove the large boulder from over your head and read the news)?  Well, it must be getting warmer in CA winegrowing regions, raising the sugar in the grapes due to the higher temperatures, and thus increasing the alcohol content in the final wine, right?

Not necessarily.  According to the CWE study, the weather patterns have had a minimal impact on grape sugars during the last twenty years:

“…an increase in heat during the growing season would contribute to an increase in the sugar content of grapes.  However, the heat index did not exhibit any statistically significant growth during the growing season..”

So what is causing the increased sugar = increased booze?  Probably the CA wine biz reaction to consumer demand. According to the study, it seems that premium wine varieties (especially reds) have seen some of the most dramatic sugar level increases – and they propose that this could be due to critics like Robert Parker giving higher scores to riper, more concentrated wines. This in turn causes consumers to demand those wines with higher scores, which causes winemakers to try to get higher scores, which causes grape growers to leave grapes hanging on the vines longer in an attempt to achieve more ripeness (and therefore raising the sugar levels in the grapes). To the study:

“In all of the models… the analysis shows a higher propensity for growth in sugar content for premium varieties, compared with non-premium varieties, even though premium varieties had higher sugar content to begin with.  This feature and the patterns of the level of sugar content among regions and varieties could be consistent with a “Parker effect” where higher sugar content is an unintended consequence of wineries responding to market demand and seeking riper flavoured more intense wines through longer hang times.”

The study doesn’t conclusively prove a link between a “Parker Effect” and rising CA wine booze levels – it merely concludes that is one logical interpretation of their results, since global warming / weather effects alone don’t account for the measured increase in CA grape sugar levels.

Still… it would explain quite a bit, wouldn’t it? And we don’t exactly have data coming out of ears disproving the link, or attributing the sugar/booze increase to something else, now do we?






  • Steve Heimoff

    You're right, there's nothing particularly new about this. There's evidence that ABV levels may actually be going down, the result of newer winemaker approaches and cooler vintages.

    • 1WineDude

      Steve – or the application of alcohol removal tech? ;-)

  • Wayne

    How about adding WATER? I know for a fact it's happening, given all the pressure from consumers (at least here in alcohol-paranoid Italia).
    Talking to our winemaker about this he mentioned that one of the reasons things are riper in the vineyard than ever before is because of modern canopy mangement, lower-yields and better chemicals that keep vines and leaves healthy, translating into more/better photosynthesis…

    • 1WineDude

      Thanks, Wayne. Interesting point about vineyard management improvements contributing to increased ripeness; but I suppose it also suggests that the implied message there is that more ripeness is better, which could be a market-driven assumption. Cheers!

      • Wayne

        Or is it that ripeness is a by-product of healthier vineyards/vines? No one likes peronospera!

        • 1WineDude


  • Jerry

    For me, it all comes down to balance (or what I perceive to be a balanced wine) in fruit, acid, tannins, and of course alcohol. I don't taste nearly as much wine as you do because I have to buy all my hooch : ). That said, much of what I taste/drink is California wine. Personally, I've tasted Cali wines at 13.5% ABV where I could actually smell the heat of the alcohol. Conversely, I've had Cali wines that were higher in ABV (15% or more) and I wouldn't have known otherwise if I hadn't peaked at the label. As always, it comes down to the individual taster and their preferences, mood, and 8 million other variables. I use reviews, wine label content, hell- even blogs as guidelines and information to aid in my wine purchases. My preference, of course, is to be able to taste before I buy. Which is why visiting tasting rooms is so much fun- except for when the winery charges $20 and they don't waive with purchase- but that's another subject all together. Cheers!

    • 1WineDude

      Thanks, Jerry. Just be careful with those blogs, ya hear?! :) Totally agree about balance and I avoided the topic in the post since it is a very factual study – abv and sugars went up. Is that bad? Sometimes, but it is never always bad. Cheers!

  • Albert

    Targeting sugar levels can often dictate vineyard management practices – yield and canopy management. Then you have the issue of amelioration, which simply dilutes the must with water to bring down sugar/alcohol levels to an "acceptable" level. These practices are not, in and of themselves, necessarily bad. However, if the motivation to manipulate is based on trends in the marketplace that certain critics influence – that is when trouble starts. I am a big fan of wines that truly represent terroir, vintage and the art of a winemaker smart enough to get the hell out of the way of greatness….

    • 1WineDude

      Well stated, Albert!

    • Wayne

      Totally agree! Everything has its reason in the vineyard and in the cellar… We all know certain practices (spraying for healthier vines, lowering yield for concentration) have their effects. What I was saying that the pursuit of healthier vines and more concentrated fruit (along with the oft-debated subject of physiological maturity vs picking for sugar levels) have the additional (and perhaps unwanted) by-product of more sugar.
      Getting out of the way of the vineyard sometimes means naturally harvesting grapes at 14-15% alcohol!

      • 1WineDude

        Another great point there, Wayne. If it is what the land is giving you, then high alcohol is not a fault, it is a fair representation of the land. Cheers!

  • Eugenia Keegan

    Two thoughts please. I would caution the use of the word "riper". Ripeness is related to maturation….this equation has a lot to do with simply picking at higher sugar. Is it riper? Best to define ripeness first.

    Second comment please, is the old adage of a conversion of .55. That is what we were taught years ago, but currently that number has changed. Might be worth doing a bit of a survey, but in Russian River Valley Pinot noir I have had conversions as high at .64. This adds "insult to injury" if you will.

    ….and then there is the Parker effect!

    • 1WineDude

      Thanks, Eugenia – fair points! I would need more detail on the conversion (I like being techy, but that one is a bit more techy than I usually get) but totally understand about ripeness (obviously I am speaking generally in the post, but I welcome discussing differences in ripeness – phenolic, etc. – here in the comments. Cheers!

  • VDP

    No thoughts on the evolution of the catalyst in fermentation, yeast? Hasn't engineered yeast become more effective in converting sugar – thus increasing alcohol even if sugars are not as high? Just sayin…..

    • 1WineDude

      VDP – There certainly has been a ton of talk lately about the evolution of yeast creating high-powered fermenting biological machines. Logically a contributing factor (though not part of the CWE study).

    • John

      Actually, no – yeast can't ferment more efficiently than the theoretical maximum, which is something like 0.62. Any observed deviation from this value indicates erroneous measurements of initial sugar and/or final alcohol. A significantly lower conversion ration may indicate incomplete fermentation – i.e. residual sugar.

  • Kathy

    Jerry – thank you for saying the obvious which doesn't get said enough.

    Honestly, I don't feel any "buzz" difference in 2 glasses of wine at 13.1, 14.3 or 15.6. Earlier this week, a friend drank 1.5 bottles of Rose at 12.5 alc and woke up tossing her cookies. So, the lesson is too much consumption, regardless of alc level, is well – too much.

    • 1WineDude

      Kathy – also depends of course on how you're feeling as well. I've been sick from one glass of Port when I had it after a day of feeling a bit under-the-weather (and not getting enough water all day). Cheers!

  • 1WineDude

    Looks like the authors of the CWE study have just released another paper on wine abv levels that is a follow-up of sorts to the one cited in this post:

    Among their conclusions:
    "Finally, to return to our main finding, we have suggested that the substantial, pervasive,
    systematic errors in the stated alcohol percentage of wine are consistent with a model in which winemakers perceive that consumers demand wine with a stated alcohol content that is different from the actual alcohol content, and winemakers are willing to err in the direction of providing consumers with what they want. What remains to be resolved is why consumers choose to pay winemakers to lie to them."

    Fascinating shizz!

  • John

    As I posted over at Dr. Vino – if 57% of wine labels under-state the actual alcohol percentage, that means nearly 43% over-state (because that chance that any individual analysis will EXACTLY match the label value is actually pretty small – especially as these analyses are being reported to 4 decimal places and alcohol labels are generally rounded to 3). And if the split is 57/43 what that means is that the non-systematic error rate (or the "lie" rate – if you will) is just 7%. Whoop-dee-doo. ;-)

    What I don't get is why people's panties get in such a bunch over this. My current favorite beer is reported at just under 5%. My second favorite beer is over 9% – you can bet that when I am out I drink the latter in half the volume or at half the rate of the former. I prefer my wines to be between 12% and 15% or so – and you can bet I drink a lot less wine when I am out than I might drink beer (part of that equation is simple economics; beer is way cheaper per unit of alcohol than wine). I prefer my Ports at 20%. My favorite cocktails weigh in at upwards of 35%. And my favorite digestif is just over 40%.

    And I'm going to get all pissy about 0.5%? No. I'm not.

    • 1WineDude

      John – makes sense, though I personally don’t pay much attention to abv in beer or wine myself. Balance and taste are most important for me, so if abv is low/hi I don’t much care so long as the components are all approaching some manor of harmony. Having said that, I do find it fascinating that consumers may *want* to be lied to when it comes to abv as suggested in the follow-up study – I really hope more is done to explore (and/or debunk) that.


    • Wayne

      Excellent post, John… and what I insist on constantly: If you're enjoying a wine at 14.5%, instead of 12.5%, just drink a little less (15cc less per glass, about a teaspoon!) to level the alcohol consumed.

      • 1WineDude

        Wayne – very “Dude” -like avatar you’ve got going there, btw. AWESOME!

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