Wine drinkers are in the dark about how many standard drinks they are consuming in bars and restaurants and could easily exceed the legal driving limit, a leading drug and alcohol expert has warned.
National Drug Research Institute Associate Professor Tanya Chikritzhs said a test by The West Australian on the number of standard drinks in individual glasses of wine in licensed premises revealed how difficult it was for people to gauge how much alcohol they were consuming.
Wine measures varied widely across venues from 120ml to 175ml, as did the alcohol content, meaning a "glass" of wine could be anything from 0.7 to 1.8 standard drinks.
A 175ml glass of shiraz at 14.5 per cent alcohol is equivalent to two standard drinks, double the recommended limit an hour for a woman who is driving and exactly her daily recommended allowance.
"People need to ask the questions: 'What is the percentage alcohol in the wine, how much is being poured' and make the mental calculations," Professor Chikritzhs said.
She would like to see all wine glasses stamped with their volume and licensed premises supplying information such as the measure of wine poured, the alcohol content or standard drink equivalent on wine lists.
Unlike beer and spirits, there are no regulations governing what measures of wine are sold in licensed venues.
Mental Health Minister Graham Jacobs has proposed wine glasses be stamped with the number of standard drinks they contain - a move Australian Hotels Association WA chief executive Bradley Woods said would be near impossible and prohibitively expensive as licensed premises would need dozens of different glasses.
Graphic designer Jade Barrett said it was a common assumption all glasses of wine were the same.
She had never asked for the alcohol content of her drink in a bar but she would in future.
"The fact that there is such a difference in different glasses of wine really makes me think twice about what I am drinking," Ms Barrett said.
