For their investigations suggested that how much wine is poured depends on the social setting, whether the wine is red or white — and even the shape of the glass.
Unlike beer, where the quantity served tends to be governed by the capacity of the bottle or can, pouring a glass of wine involves a lot more guesswork. In the United States, a standard serving of wine is 5 ounces (about 148 milliliters), according to the National Institute on Alcohol Abuse and Alcoholism
. In the UK, wine served by the glass in pubs and restaurants is generally offered as 125ml or 250 ml measures.
But serving wine at home is rarely such an exact science. In a domestic setting, one person’s ‘glass’ can sometimes be another’s Bacchanalian
excess, with serious consequences for over-consumption.
In the recent study
, entitled ‘Half Full or Empty: Cues That Lead Wine Drinkers to Unintentionally Overpour’ published in Informa Healthcare’s Substance Use and Misuse
, those tested were requested to pour what they considered to be a normal serving of wine using different types of glasses in different settings. The study found a wide divergence of results depending on the type of glass used.
Participants poured around 12 percent (almost one-eighth) more wine into a wide glass than a standard one. A similarly generous serving of wine also resulted when those taking part poured a glass whist holding it, rather than the more formal setting of pouring to glasses set on a table.
Laura Smarandescu, an assistant professor of marketing at Iowa State, commented,
“People have trouble assessing volumes. They tend to focus more on the vertical than the horizontal measures. That's why people tend to drink less when they drink from a narrow glass, because they think they're drinking more."
Researchers tested six environmental permutations seeking to understand how each might govern the amount of wine poured. In a formal setting, the size of the dinner table didn’t seem to matter much. On the other hand, the contrast between the glass and color of the wine did make a significant difference: when pouring white wine into a clear glass, participants poured 9 percent more than pouring red, which had a greater contrast to the glass.
Lead author of the study, Doug Walker, an assistant professor of marketing at Iowa State said it's easy to lose track of how many drinks you've consumed, if you’re pouring more than you realize:
"If you ask someone how much they drink and they report it in a number of servings, for a self-pour that's just not telling the whole story. One person's two is totally different than another person's two."
"Participants in the study were asked to pour the same amount at each setting, but they just couldn't tell the difference."
With growing concerns over an obesity epidemic, the researchers contrasted the move to portion control and the individual "feeling full" in the case of food, with the more nebulous ‘measurements’ of wine-servings.
Whilst eating too much at a social occasion might just leave an individual feeling ‘pigged out’, drinking too much, sometimes unwittingly in the case of ‘guesstimates’ of how many glasses of wine, will have more immediate and potentially more serious consequences.
According to Smarandescu, the study demonstrates the need to educate people about how to measure a proper serving size of alcohol, adding,
“I think this helps us understand drinking behaviors to see how these cues influence individual pours. When you add this information about how people pour, to survey data of how much people drink, then you have a more complete picture about how people drink,"
So, if you’re concerned about over-indulgence when uncorking that next magnum of popularly-priced plonk or, less altruistically, just want to ensure your hospitality doesn’t extend as far as a second bottle of Château Lafite Rothschild
, so lovingly laid down all those years ago, the Iowa and Cornell researchers have a few tips:
• Use a narrower, taller glass in preference to a wider, taller one
• Never use a wide-necked glass
• Never stand and pour with bottle and glass in hand
• Always pour to glasses on a table, never to glass in hand
Oh, and one last piece of advice not covered by the Iowa and Cornell researchers: when having friends or guests round, never be tempted to serve wine with the aid of a measuring jug.
Note for US readers: “GOVERNMENT WARNING: (1) According to the Surgeon General, women should not drink alcoholic beverages during pregnancy because of the risk of birth defects. (2) Consumption of alcoholic beverages impairs your ability to drive a car or operate machinery, and may cause health problems.” Other countries have issued similar health warnings.