Here is an argument I’ve heard several people make for the unreliability of wine criticism.

(1) Wine criticism requires excellent judgment

(2) The consumption of alcohol impairs judgment.

Therefore, wine critics have impaired judgment and their evaluations cannot be accurate.

Of course, the immediate response to this argument is that wine critics typically spit when they are evaluating wines.  But when you look at the numbers that doesn’t quite let wine critics off the hook. Some alcohol is absorbed through the mouth when critics are tasting, swishing and spitting. Does that matter?

There is not a lot of science on this but the one report I found that clearly addresses this issue was from The Wine Spectator reporting on a study done in Wine Studies, 2012. The study measured blood alcohol content from drinking vs. spitting.

Ten participants were given 15 milliliters (approximately a half-ounce) each of five white wines and five red wines to swish and spit, rinsing with water in between, over the course of one hour; their BAC was measured 15 minutes after the last wine. A week later, the experiment was repeated, but the subjects drank 15 milliliters of each wine. No food was consumed, and the wines ranged from 11.5 percent to 13.5 percent alcohol.

Even though the individuals drank only 150 milliliters (about 5 ounces, or 1 glass of wine), five of them measured a BAC above the Netherlands’ legal limit of 0.05 percent (versus 0.08 in the United States). In contrast, when volunteers spit the samples, they all had low (but detectable) BACs under the legal driving limit, averaging 0.0026 percent.

.0026 percent BAC doesn’t seem like much alcohol consumption but that depends on how many wines you’re  tasting and spitting and how many times you taste each wine. Critics report tasting varying amounts of wine depending on the tasting event. At the Decanter awards, critics  taste 85 wines. Many competitions may be twice that. Fred Swan says he tastes around 40 wines for a regional tasting at a winery, more if they’re in a hurry. Various critics report 20-30 wines in a day when tasting for a publication. Eric Asimov reports that some critics will taste 100 wines at a sitting.

It is difficult to compare the study with actual tasting panel behavior. The subjects in the study tasted only 1/2 ounce of each wine, a very small amount. Most critics would likely taste and spit about an ounce of wine per sample since most would sample a wine more than once.

So in the study, 5 oz. of spit wine produced a BAC of .0026. In a tasting where 40 wines are tasted, using the 1 oz. figure for each wine, 40 ounces would be tasted and spit. That is eight times the consumption in the study. That is an average BAC of .0208, well under even Europe’s legal limit. But for the Decanter awards, 85 wines  would be 17 times the amount in the study. That is a BAC of .0442, very close to the legal limit in Western Europe. And in those tastings that require 150 wines be tasted—that would be over the limit even in the U.S.

Of course there is one important caveat. Wine tastings can take place over several hours, especially the large ones, with a break for food. I doubt earnest spitters would  be a danger on the roads.

But nevertheless in large tastings there is probably some degree of impaired judgment, not to mention the real problem of palate fatigue when tasting that many wines.

Does this undermine wine criticism? I think the palate fatigue is the real threat. The alcohol consumption less so. Wine critics in many contexts are engaged in aesthetic evaluation which involves being sensitive to the expression of the object they’re evaluating. I think very mild inebriation likely makes you more sensitive to the sensory properties of the wine. We want to be in a frame of mind where we have a kind of sympathy for the object in order to grasp as many properties as possible. A bit of alcohol enhances that sympathy.

How much alcohol do I consume when writing a review? I don’t spit. Wine is for drinking and you get a better sense of a wine by swallowing. But I review only 1 wine at a time over 2 days to see how oxygen affects it. The basic evaluation is made with one  3 oz. tasting pour, with a follow up later in the evening to do the music pairing.