Many countries require labeling and reporting of alcohol levels in beverages, but the accuracy of these claims may be far from perfect, at least in the case of wines.

A 2011 paper by the American Association of Wine Economists, “Splendide Mendax: False Label Claims about High and Rising Alcohol Content of Wine,” analyzed data derived from nearly 130,000 wine samples imported to Canada from around the world over 16 years to examine the veracity of their alcohol content labeling. Because there has been speculation that increases in alcohol content might be attributable to climate change and rising temperatures in grape growing regions, the study’s authors look at temperature data, as well, and evaluate this hypothesis.

The study’s findings include:

• Over time, wines have on average become more alcoholic. The annual rate of increase ranges between 0.1% and 1.0% per year (depending on a country’s climate and culture, and the wine varietal, red or white). This resulted in an overall increase in the alcohol content of wine of 1.6% to 16.0% percent over 16 years across the nations studied.
• In terms of labeling, 57% of the wines analyzed were tested to actually be stronger than was declared on their label. The average alcohol content was 13.6%, while the average reported alcohol content was only 13.1%.
• The nations producing the most consistently understated bottles were Argentina, Chile and the United States. However, all of the winemaking countries analyzed in this study, including Australia, France, Italy, New Zealand and Spain, underplayed alcoholic strength.
• European regulations only require that the label strength is not more than 0.5% different than the actual alcohol content. Some other nations allow for up to a 1% margin of error in labeling.
• Changes in the heat index in growing regions plays only a modest role in these new industry patterns: “While other measures of climate might have additional effects that we have not measured, our findings lead us to think that the rise in alcohol content of wine is primarily man-made.”

The study’s authors conclude: “In many places the rise in alcohol content of wine is a nuisance consequence of choices made in response to evolving demand for wine having more intense, riper flavors. Specifically, label claims appear to be biased towards a perceived norm, a ‘desired’ alcohol percentage to report for a particular wine — red or white, New World or Old World — with the size of the bias depending on the extent to which the actual alcohol content differs from that norm. The implied values for these norms revealed by our analysis are approximately 12.8% alcohol (by volume) for Old World red, 12.3% alcohol for Old World white, 13.2% alcohol for New World red, and 12.7% alcohol for New World white.”

Tags: food, nutrition, obesity