A new study examines what effect the size of wine glasses has on wine sales. Ben Canaider wonders whether that means the glass is better half full or half empty?
A study from the UK, published in the BMC Public Health Journal by scientists from Cambridge and Bristol Universities, suggests people drink a “significantly greater amount of wine when their beverage is served in a larger glass.”
Over a five-month period in 2015, wine sales at a local Cambridge pub were analysed on a two-week cycle. For two weeks, wine by-the-glass sales were served in a 300ml capacity glass. For two weeks after that 370ml glasses were used, and for two weeks after that, 250ml glasses—for five months. No matter what capacity glass was being used, the standard wine pour was 150ml.
When this standard pour was served in the larger 370ml capacity glasses, wine sales increased more than 11 per cent: up 14.4 per cent in the bar and 8.2 per cent in the restaurant.
Lead author of the study, Dr Rachel Pechey, said it is not yet clear why this is the case.
“One reason may be that larger glasses change our perceptions of the amount of wine, leading us to drink faster and order more,” she theorised.
Dr Pechey said that more research is needed to understand and confirm the link between larger glass size and increased wine sales and consumption. She also suggested that liquor licensing regulations might need to take this into account. She wondered, “Could it be an alcohol licensing requirement that all wine glasses have to be below a certain size?”
That may well be the case. I mentioned this study to a food and beverage manager I’m on friendly terms with, and he became concerned about responsible service of alcohol and how glass sizes might affect that. Then I had a quiet drink with a wine rep, who saw sales potential—doing a back-of-the-envelope calculation about how much it would cost her to get a fleet of wine glasses as big as your head into her favourite on-premise account.
Putting sales opportunities and service responsibility to one side for a moment, glasses—or stemware as they are known by wine cognoscenti—have had a major overhaul over the last 30 years.
Remember the early 1980s? The 190ml Paris Goblet was the wine glass du jour in most eateries.
“Larger glasses change our perceptions of the amount of wine [we drink], leading us to drink faster and order more.”—Dr Rachel Pechey, University of Cambridge
Also at this time, there was a lot of Waterford crystal— wonderful to see on a table setting and a delight to hold and admire —even if their shapes and thick lips do make all wine taste virtually the same.
Which are qualities the game-changing glassmaker, Riedel, would have us believe are critical to wine-glass manufacture and wine appreciation. Besides the aesthetics of their wine glass, and the more tactile, cut-rim edge that Riedel crystal stemware offer, they have done much to promote the idea that different wine styles need a dedicated wine bowl atop the stem—with the shape and dimensions of the bowl designed to bring out the best in the wine.
Capacity is also key to the design, and indeed Riedel make one Pinot Noir or red Burgundy glass that at full capacity holds 1095ml of wine.
On top of aesthetic considerations and dedicated stemware for each style of wine you offer on your wine list, there is also a strong customer expectation for quality glasses. The logic goes that if the customer is paying top dollar for a bottle of wine, the customer wants a wine glass that is big and costly and flash and made by hand by an Austrian wine-glass artisan. Whether the wine glass makes the wine any more enjoyable—on a strictly analytical level—is not important.
What is tricky about this wine glass research is the bit about a standard glass, or pour, or unit of alcohol when served on-premise. Not that I am for a microsecond suggesting the need for regulation in this area, but it does seem odd that a container of alcohol sold off-premise must display the number of standard drinks it holds, but a glass of wine sold in a bar or restaurant doesn’t.
The formula for calculating a standard drink is volume multiplied by alcohol multiplied by 0.789. For example, one stubbie of 375ml full-strength beer at 5 per cent ABV (alcohol by volume) equates thusly: 0.375 X 5 X 0.789 = 1.5 standard drinks.
The only rider in all of this is where you are in relation to sea level and and how hot or cold it is in the bar you are serving the standard drink. Yes, 0.789 is the specific gravity of alcohol at sea level, at an ambient [room]temperature of 20° Celsius. The higher you go both in terms of altitude and temperature, the lower the specific gravity. For instance, if you’re in the tropics, at sea level, and it is 25° Celsius, then your aforementioned stubbie would be: 0.375 X 5 X 0.785 = 1.47 standard drinks. But there is no regulation yet, and the guidelines published by the Australian Government’s Department of Health (see below) are a little broad.
There are two worthwhile observations in these guidelines: one is the ABV value given for red and white wine: 13 per cent and 11.5 per cent respectively.
The other observation is the ‘average restaurant serving’: 150ml. There are no stricter guidelines than this, and indeed wine pours can range from 120mls to 180mls.
Mentioning the volumetric size of your by-the-glass pours is, however, something better wine lists do.
It’s grown-up and treats your customers with attention and care. And pouring said volume of wine into a pretty big wine glass looks like a no-brainer to me.
Number of standard drinks
13 per cent alcohol volume
100ml standard serve = one standard drink
150ml average restaurant serving = 1.5 standard drinks
750ml bottle = 7.7 standard drinks
Two-litre cask = 21 standard drinks
Four-litre cask = 41 standard drinks
11.5 per cent alcohol volume
100ml standard serve = 0.9 standard drink
150ml average restaurant serving = 1.4 standard drinks
750ml bottle = 6.8 standard drinks
Two-litre cask = 18 standard drinks
Four-litre cask = 36 standard drinks