Larger Wine Glasses Encourage More Drinking, Study Finds

University of Cambridge researchers found that wine sales were 9% higher when larger glasses were used

Source: WSJ

By Denise Roland

Dec. 21, 2015

Bartenders and waiters love to hear a wine drinker say, “I’ll have another.” Could the glassware they use make this happen more often?

Researchers at the University of Cambridge say it looks like larger wineglasses encourage patrons to drink more, even when serving sizes are held steady. A small study earlier this year in a local pub-restaurant found that wine sales were 9% higher when larger glasses were used to serve the same standard portion of 175 milliliters, or just under 6 ounces.

“It may be people perceiving the glass to contain less and drinking it faster,” said Theresa Marteau, director of the university’s Behavior and Health Research Unit, who led the research. Or it could stem from a phenomenon known as “unit bias,” meaning that drinkers judge the same volume of wine in a larger glass as less than a single portion, making them more likely to order another one.

Although small-scale, the study “tells us something is going on,” said Prof. Marteau, whose research focuses on how to encourage healthier behaviors. “Quite how large [the effect] will be when we roll it out into other contexts, we don’t quite know.”

Pub patrons in London found the results surprising. “I drink fast all the time because I’m a fast drinker,” said Rob Adam, a 22-year-old having a beer with colleagues. David Walton, a 42-year-old information-technology director, said he believed his pace of alcohol consumption was set by the fastest drinker in his group-usually a friend named Gus. “I call it the Gus effect,” he said.

Still, the research adds to a mounting pile of evidence, mostly in food, that “supersizing” portions, packaging or tableware leads to higher consumption. A recently published review found more than 70 studies on the topic and concluded that downsizing on all fronts could bring about a “meaningful” reduction in food intake.

One of the few other studies on alcohol consumption, by the University of Bristol, found that beer drinkers took more time over a pint presented in a straight-sided glass than a curvy one. That gives Prof. Marteau more confidence that the result of her wineglass study has legs.

She is aiming for a larger-scale trial involving several pubs, bars and restaurants across the U.K. One is already under way with a few more in the pipeline, she said. Her pitch is simple: It’s a “win-win” situation. “They want to find out what glasses might increase their sales, and we’re interested in what glass sizes might decrease them.”

James Hickey, general manager of the Pint Shop in Cambridge, where the first experiment was conducted, said “getting amazing data analyzed for free” outweighed the work of clandestinely switching the bar’s wine glasses.

For the experiment, Mr. Hickey cycled through three glass sizes-the standard 300 milliliters, a smaller 250 milliliters and a larger 370 milliliters-two weeks at a time for 16 weeks. To prevent skewing the results, he instructed bar staff to “just not say anything” to customers unless asked directly. In the end, he said, nobody mentioned noticing the changes.

The larger glasses generated a 9% boost in revenue compared with the midsize ones, while the smaller glasses had a negligible effect on sales.

“As you would imagine,” said Mr. Hickey, “we’ve started using the larger glasses, which I know wasn’t the reason behind the study from Cambridge University’s point of view.”

The research has piqued the interest of local officials, police officers and others interested in reducing alcohol-related violence in Cambridge’s city center, who had Prof. Marteau’s group present the results at a meeting earlier this month.

“If the results of future, larger studies did support the emerging evidence around glass size, then potentially this could be considered by policy makers,” said Joe Keegan, head of alcohol strategy for Cambridgeshire County Council, the local government.

Efforts to curb supersizing in food and soft drinks have generally focused on what is served, not what it is served in. McDonald’s Corp. phased out its “Super Size” french-fry and soft-drink portions in 2004. In the U.K., several big confectioners, including Mars Inc., Nestlé SA and Mondelez International Inc., in 2013 pledged to cap their chocolate bars and snacks at no more than 250 calories a portion. Some initiatives, such as former New York Mayor Michael Bloomberg’s attempt to ban the sale of sodas larger than 16 ounces, have foundered amid legal challenges.

The U.K. alcohol industry is accustomed to strict serving sizes under decades-old laws. But regulating the vessel rather than the volume could prove challenging.

“Asking a publican to use glassware that encourages your customers to drink less is counterintuitive,” said Ben Taylor, general manager of the Taproom pub in north London. “I don’t think you’d get a lot of support for that.”

Up the street, Jimmy Craig, floor manager of bar-restaurant the Dolls House, wondered whether regulating glass size could help curb the late-night drinking of some of his rowdier customers.

Then again, “if someone wants to go and have a mad, wild night, I don’t think the size of glass is going to stop them.”