But, she said, the really steep increase in size came in recent times, almost doubling from 232 milliliters in 1990-1993 to a whopping 449 milliliters in 2016-2017.
The dimensions of the glasses, she said, reflected the overall size of the bowl, rather than the serving size of the wine. But in Britain, portions can appear surprising.
A “large” glass of chardonnay or merlot in London, for instance, usually means 250 milliliters, the same amount a French bistro might offer in a carafe to be shared by a more abstemious pair. In Britain, wine glasses also come in medium — 175 milliliters — and small, around 125 milliliters.
But, as Dr. Marteau’s report notes, the smallest size “is often absent from England’s wine lists or menus,” despite British regulations requiring bars and restaurants to “make customers aware of these smaller measures.” Just one large glass, by contrast, represents one-fifth of “the weekly recommended intake for low-risk drinking,” the report said.
Bigger glasses, the report says, contribute to higher consumption and bigger profits in bars and restaurants, and the 250-milliliter offering is increasingly prevalent. And wine sold in Britain is stronger now than it was a few decades ago, so larger glasses can mean a higher intake of alcohol.
The expansion of glass sizes seems rooted in a blend of historical developments, modern commercialism and a taste for wine itself, whether sipped or swigged.
Historically, the removal of some taxes on glassware in the mid-19th century, coupled with more sophisticated, automated glass production could have contributed to gradually increasing sizes. But the big push for bigger glasses may have originated not so much in the desire to drink more wine as to derive greater pleasure from allowing finer wines to breathe in airier vessels.
“Two changes in the 20th century probably helped to increase glass sizes further,” the Cambridge study said. “Wine glasses started to be tailored in shape and size for different wine varieties, both reflecting and contributing to a burgeoning market for wine appreciation, where larger glasses were considered important.”
“From 1990 onward, the U.S. market’s demand for larger wine glasses was met by an increase in the size of glasses manufactured in England, where a ready market was also found,” the researchers wrote. Bartenders were not slow to capitalize on the new sizes, and neither were their clients.
“A further influence on wine glass size may have come from people running bars and restaurants, as well as their customers,” Dr. Marteau’s study found. “If wine sales increased when it was sold in larger glasses, this may have incentivized vendors to use them more. Larger wine glasses can also increase the pleasure from drinking wine, which may in turn increase the desire to drink more.”