Why is wine getting hotter?

By Felix Salmon
June 21, 2011
formal academic paper proving it:

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I’ve long suspected that this is true, but now there’s a formal academic paper proving it:

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.

Essentially, people like to think of themselves as sophisticates who go to art-house movies, even if in reality they’re much more likely to sit slack-jawed in front of some reality TV show. In the case of wine, they like the idea of buying something grown-up, with a relatively modest amount of alcohol; when it comes to drinking what’s inside, however, the more heat the better. So wine labels consistently show lower alcohol content than what’s inside.

This is especially true in the new world. Out of 43,908 tested new world wines, 24,561 under-reported their alcohol content, with the reds averaging 14.1% alcohol while claiming just 13.6%, and the whites averaging 13.5% while claiming to be 13.1%.

Interestingly, the smaller number of wines which either over-reported their alcohol content or got it exactly right all reported pretty much the same levels of alcohol: 13.1% or 13.2% for whites, and 13.6% or 13.7% for reds. On average, it seems, wine will just say that it’s 13% if it’s white and 13.5% if it’s red, but in reality it’s likely to be higher than that.

So wine is hot, and getting hotter. Is this a global warming phenomenon? No:

The coefficient on the heat index is approximately 0.05, suggesting that a one-degree Fahrenheit increase in the average growing season temperature everywhere in the world would cause the average alcohol content of wine to increase by 0.05 percentage points; it would take a whopping 20 degree Fahrenheit increase in the average temperature in the growing season to account for a 1 percentage point increase in the average alcohol content of wine.

Instead, it’s a style thing:

We can expect Old World (European) wines to have about 0.63 percentage points less alcohol than wine produced in the New World (the Americas, Australia, New Zealand, and South Africa)… compared with France, three countries produce somewhat lower-alcohol wine (Canada, New Zealand, and Portugal) while the rest produce higher-alcohol wine, with the effects being most pronounced for Australia (0.55 percentage points higher on average) and the United States (0.85 percentage points higher on average).

In Australia, red wine has increased in alcohol content by a whopping 1.4 percentage points over the past 18 years: it’s pretty much an entirely different drink, now, to what it was as recently as the mid-90s.

And yes, the wineries know exactly what they’re doing.

It is relatively inexpensive to measure the alcohol content of wine reasonably precisely (though some of the devices used may entail larger measurement errors), and it is necessary to do so to be informed enough to comply with tax regulations, at least in the United States. It is also an important element of quality control in winemaking. Consequently, we speculate that commercial wineries for the most part have relatively precise knowledge of the alcohol content of the wines they produce and that the substantial average errors that we observe are not made unconsciously. This speculation is based in part on informal discussions with some winemakers who have admitted that they deliberately chose to understate the alcohol content on a wine label, within the range of error permitted by the law, because they believed that it would be advantageous for marketing the wine to do so. In one instance, we were told specifically that the stated alcohol content was much closer to what consumers would expect to find in a high quality wine of the type in question.

If you want to explore the world of high-quality, low-alcohol wines, then, don’t always trust what you see on the label. And doing so is going to be much harder than it used to be. In 1992, white Bordeaux wines averaged 11.7% alcohol; since then they’ve been getting hotter at a rate of 0.35% per year, putting them at 12.5% today. And in the new world the numbers are much higher: Chilean reds, for instance, averaged 12.3% alcohol in 1992, and have been growing in alcohol at a rate of 0.82% per year since then. That means they’re now at 14.2% and rising.

How much further can this trend go? We’re beginning to see a backlash to high-alcohol wines, but I fear that the backlash is simply manifesting itself in lower numbers on the label, rather than lower alcohol levels in the bottle. Winemakers are convinced they know what consumers want — and I fear they’re entirely correct. And consumers, clearly, love to be lied to. So this is likely to continue for a while yet.


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“and the whiles averaging 13.5% while claiming to be 13.1%.”. Think ya meant ‘whites’.

Hey, no math errors permitted from the finance blogger!

“In 1992, white Bordeaux wines averaged 11.7% alcohol; since then they’ve been getting hotter at a rate of (0.35%) per year, putting them at 12.5% today. And in the new world the numbers are much higher: Chilean reds, for instance, averaged 12.3% alcohol in 1992, and have been growing in alcohol at a rate of (0.82%) per year since then. That means they’re now at 14.2% and rising.”

I think you meant .035% and .082%, which multiplied by 20 years is .7% and 1.94%, which gets you 11.7 ->12.4, and 12.3 -> 14.2%, or pretty close.



Posted by REDruin | Report as abusive

erp! your .035% should actually be .04%, and your .082 should be .092%, unless you are rounding very generously. Teach me not to edit myself.


Posted by REDruin | Report as abusive

Hey RED, time to head back to Math 101. 0.35% is correct.

take 11.7 and multiply it by 1.0035, which is an increase of 0.35%. Then take the result and multiply that by 1.0035. Do that 19 times and you have 12.5

Maybe you’re the guy who engineered the mirror for the Hubble telescope?

Who’s feeling stupid now?

Posted by fred999 | Report as abusive

Ah, he’s using redactive compounding interest, instead of simply increasing the ‘% of alcohol content year by year’. But he’s directly referring to the alcohol content as an additive, not a compounding multiplier, hence my confusion. 1.0035^20 is not how I’d have run a per year increase in alcohol, but at least his math works out now.

So, yes, I do know how to work compounding interest factors, which I think got covered in them dem 300 level Finance courses. Heh. There was simply no wording to get me thinking he was using compounding instead of straight years/total change = average. Sorry, I look for averages more then reducing bases!


Posted by REDruin | Report as abusive

“Essentially, people like to think of themselves as sophisticates who go to art-house movies, even if in reality they’re much more likely to sit slack-jawed in front of some reality TV show.”

Hey! Stop talking about me behind my back!

The direct “evidence” for deliberate understatement of alcohol content in wine, such as it is, comes down to one unnamed source. It is interesting that alcohol content has risen historically, and that it is higher in newer viticultural regions. I suspect that the market for high-end wines plays little or no role in this. It’s a separate market. We slack-jawed types, who drink most of the world’s vin ordinaire, prefer the most buzz for our Two Buck Chuck. Improvements in fermentation technique have probably served us well.

Posted by jbernar | Report as abusive

RED – Thanks for your good-natured response.

Posted by fred999 | Report as abusive

Funny, this is something that my wife and I have mused in the past but that I shrugged off as me not having eaten enough or me having been a lightweight (hardly) that day. It’s nice to see that maybe I wasn’t crazy after all.

Posted by spectre855 | Report as abusive

As a journalist you are very cleaver at using facts the way you want, but unforunately not very well informed. There is a strong movement among Californian winemakers to back down the alcohol content “not” because it is getting people drunk but because of how it affects wine. And European wines tend to be much lower in alcohol than the numbers you use.

I just posted a rebuttal on LinkedIn that should be read by about 25,000 wine professionals who I hope reach the 5 million wine lovers out there…may you never be read again.

I think most of us (if not all) would be highly insulted at the profile you paint of us. I also asked any of these wine professionals to stand up and let me know their name…anyone who on a consistent basis can determine a wine that is .5% (or less) higher in alcohol content than another. Seriously doubt anyone will claim the ability.

And by the way it is because of sensationalizing journalist like you that the WSWA can mount a drive for bills like HR5034 (now dead) or HR 1161 among politicans.

Posted by WineLover | Report as abusive

Really, WineLover? No wine professional is capable of doing a basic chemistry experiment? Are any of them capable of adducing facts that support their arguments, or do most arguments among wine professionals consist of saying that the other side is not very well informed, and then producing random factoids of various levels of credibility that do nothing to address the other side’s actual points?

Posted by dWj | Report as abusive

dWj…of course any professional can do a chemistry test..I meant by taste as most people do…haven’t seen to many wine drinkers carrying around test kits with them at local restaurants.

I have yet found anyone who agrees with your side…but then the hundreds of Californian winemakers who are starting to produce wine with lower alcohol is just another ramdom factoid?

I just came back here to see if my response had been deleted, but promise not to return again.

Posted by WineLover | Report as abusive

Hate to argue with a wine lover, but I can’t find anything (other than the silly crack about art movies)in this article that doesn’t reinforce what dozens of other wine writers have been saying for years. To wit: that regulations allow winemakers to misstate the actual ABV in wine; that many winemakers believe that consumers like high-alcohol wines and that they are just responding to market demand, and that you shouldn’t necessarily trust the ABV % printed on the label.

And as for winemakers jumping off the high-alcohol bandwagon, I’ll believe it when I see it. Like fruit bombs and over-oaked chardonnay, as long as wine critics keep giving these wines high marks the winemakers will keep making them, despite what they tell the press.

Posted by safewine | Report as abusive

You should learn a little more about wine making and what ever your next subject of choice is. Wine professionals are all laughing at you.

Posted by Goddu | Report as abusive