If you've ever woken up surprised by how badly you feel after a couple of glasses of wine you so innocently sipped the night before, scientists may have at least a partial explanation. Reporting in the Journal of Wine Economics, University of California researchers say that among the nearly 100,000 bottles of wine they sampled from around the world, almost 60% under-reported how much alcohol was in each bottle. And while the discrepancy was on average quite small, at just 0.42% more alcohol than labeled, it doesn't appear to be accidental—the study suggests winemakers are falsely reporting in part to meet buyer expectations for particular wines, reports the Telegraph. Among the biggest offenders: Chilean and Spanish reds, and Chilean and American whites.
"Wineries may have incentives to deliberately distort the information because they perceive a market preference for a particular range of alcohol content for a given style of wine or for other reasons, such as tax avoidance," the researchers write. (Their example: The US tax rate jumps from $1.07 per gallon for wines with 14% alcohol or less to $1.57 per gallon for wine between 14.1% and 21% alcohol.) "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," the study asserts. Researchers also found a tendency to overstate the alcohol content in wine that has relatively low alcohol content. One UK consumer group is calling for evidence-based labeling that includes a calorie count, which Wine Spectator says is now required by the FDA at chain restaurants in the US. (Red wine has arsenic, too.)