Wine labels understating true alcohol content, study says
Buyers of Argentinian and Chilean wines are getting more booze than they bargain for, research has found.
Researchers at the University of California Davis tested 100,000 bottles of wine from around the world. They found 60 per cent of the bottles had, on average, a 0.42 per cent higher alcohol content than was stated on their labels.
The study found winemakers had "a tendency to overstate the alcohol content for wine that has relatively low actual alcohol, and a tendency to understate the alcohol content for wine that has relatively high alcohol content".
Lead author Professor Julian Alston told the Telegraph that even this small discrepancy could affect unsuspecting consumers' health and safety.
"A discrepancy of 0.4 percentage points might not seem large relative to an actual value of 13.6 per cent alcohol by volume, but even errors of this magnitude could lead consumers to underestimate the amount of alcohol they have consumed in ways that could have some consequences for their health and driving safety," he said.
"In particular instances the discrepancies could be much larger than average.
"An average error of 0.4 percentage points is much more significant compared with the typical range for wines in a particular category, for instance, Napa Valley Cabernet might be expected to have alcohol content within the range of 13.5–14.5 per cent alcohol by volume, and an average error of 0.4 percentage points is large in the context of this range."
Wines with the greatest margins of error came from Chile, which had an alcohol percentage difference of -0.27 between alcohol content advised on the label and that the wine actually contained, followed by Argentina with -0.24, the United States with -0.23 and Spain with -0.21.
New Zealand had the second lowest discrepancy of the 11 countries surveyed, with a -0.06 percentage difference.
The study, published in the Journal of Wine Economics in December, attributes the discrepancy to factors including "climate, evolving consumer preferences, and expert ratings".
"Winemakers perceive that consumers demand wine with a stated alcohol content that is different from the actual alcohol content, and winemakers err in the direction of providing consumers with what they appear to want.
"What remains to be resolved is why consumers choose to pay winemakers to lie to them."