Wine labels underestimate the degree of alcohol

In this study, scientists at the University of California analyzed 127,406 bottles of wine around the world and found that nearly 60 % of samples contained slightly more alcohol than the labels predicted. For example, the data showed that the average actual alcohol content in most wines was 13,56 % of alcohol by volume while the average reported by the labels was 13,15 %. This trend has been observed in both red and white wines., and the difference was greater on wines from North America than those from Europe.

As a matter of fact, it's not really a surprise. For some years, the media reported an alleged rise in alcohol in wine around the world. In 2014, The Guardian had highlighted the issue and suggested the role of climate change in this trend. Warmer temperatures make grapes sweeter, and sweeter grapes produce more alcohol. Although this observation is logical, this does not explain why the winegrowers fail to inform consumers about the new alcohol content. It is quite easy and inexpensive to measure the alcohol content, therefore the inaccurate labels appear to have been made on purpose.

According to the study, the reason for this underestimation may be purely economic. Many wine lovers have high expectations about the type of wine they consume, and when the wine does not meet these expectations they prefer another wine. Researchers reported that some winemakers have explicitly stated that they deliberately choose to underestimate the alcohol content on a particular wine label, without exceeding the margin of error provided for by law, "Winegrowers could be encouraged to give false information by perceiving a market preference for a certain degree of alcohol depending on the type of wine".

Of course, this difference could be a simple error or a smoothing of all of its production, but the researchers note that it is simple and inexpensive to know precisely the alcohol in wine. So, why the winegrowers would want to rig the numbers ?

Although this report shows that small differences in the alcohol content of the wines studied, The Guardian reported an overall average increase of 2 % in the last two decades. Although some may believe that the increasing alcohol content in wine is a good thing, just a difference of 1 % changes a lot of things in alcohol content and consumption limits. Many winegrowers believe that a wine should never have an alcohol content higher than 14 %. Unfortunately, this global trend could mean that real wine may one day become a thing of the past.

Another explanation tends to explain the gap between European wines and North American wines: Taxation. Indeed, the United States tax rate is higher for wines that are over 14 % of alcohol by volume. By indicating less than this content, the winegrower makes significant savings. The United States tax rate goes from 1,07 $ per gallon for wines containing 14 % of alcohol or less at 1,57 $ the gallon for wine between 14,1 % to 21 % alcohol.

In France - and the whole European Union —, the alcohol content of the wine must be mentioned on the label with a tolerance of 0,5 % by volume (art. 54 of EC regulation n ° 607/2009 of 14.7.09). Therefore, a wine with an alcohol level of 13,5 % can actually contain between 13 to 14 %. In addition to this margin of acceptance is added, in practice, a margin of error of 0,2 % on measurement. The tolerance is increased to 0,8 % for wines benefiting from a PDO or a PGI, stored in bottles for more than 3 years, for most sparkling wines and liqueur wines as well as for wines made from overripe grapes. All these margins can theoretically lead to a difference of 1,5 % in relation to the indicated alcohol content.