In this day of booze buses, we all know we have to watch what we drink when we go out for dinner. But what about the alcohol in our food could that put us over the limit?
Reporter Dr Andrew Rochford makes it his mission to find out if eating something like a brandy-soaked triple-layered trifle would be enough to put him over the legal limit.
Alcohol adds flavour to any dish, and tenderises meat, so cooks love it. The common perception is the booze just boils away in the cooking process. But that's not always so, says Dr Simon Worrall at The University of Queensland.
"In the case of something like a Christmas pudding where you just flame the alcohol, you leave most of the alcohol behind something like three-quarters of the alcohol that you use actually stays, so it's the equivalent of drinking it," he says.
Dr Worrall says a dish can retain anywhere between five and 85 percent of the alcohol you've poured in. How much is left depends on the cooking method. A casserole where the meat is simmered for say, an hour will still have 25 percent of the alcohol added. But in desserts it can equal a massive 75 percent.
So is that enough to affect your driving?
At this Brisbane restaurant, celebrity chef Alastair McLeod has created a three-course menu, with quite a kick.
"We've got Atlantic salmon cured with a Scottish malt whisky. That's been going for about 48 hours," says Alastair.
The rest of the menu is a choice of three main courses: wild barramundi poached in a champagne sauce; chicken and scallops with pernod, and beef in red wine sauce. Dessert is a whisky parfait with prunes or strawberries in whisky caramel.
Surprisingly, the alcohol level of this meal isn't unusually high for a restaurant menu. We'll be feeding it to six friends who'll be breath-tested before and after the meal. To see just what the alcohol in the food can do on its own, they're drinking water only with their meal.
Sergeant Ross Whittaker from the Queensland Police Service will monitor their alcohol levels. Does he think they're going to blow over the legal limit? "It's hard to say it depends on how much alcohol is in the food and how much food they eat," he says.
First, Sergeant Whittaker breathalyses our guinea-pigs to make sure no-one's had a sneaky one on the way. They all clock in at zero.
Reporter Andrew is breath-tested too because although he isn't going to eat the meal, he is going to eat a kilo and a half of the finest French chocolate laced with Irish Baileys whisky liqueur. Alastair says they contain about a third of a bottle of alcohol.
The six friends finish their dessert, the last of their three courses and Andrew's eaten about 38 of his liqueurs (and feels none too well) far more than anyone normally would but maximum alcohol is wanted for this test.
After three courses soaked in whisky, champagne, pernod and red wine, will the diners blow over? Everyone blows 0.00 and it's looking like everyone will all be driving home until David's reading. His reading goes up and up and he is almost three times the legal limit at 0.14 … Or is he?
Immediately after eating or drinking, alcohol is retained in your mouth. It soon evaporates, but if you're breath-tested straight away, it can give a false reading. That's why if you blow over, your blood is tested 20 minutes later to get an accurate reading.
"The sauce was extremely strong, you could just taste it, it was nearly pure alcohol, so it'll be interesting to see what happens in 20 minutes time," says David.
David has his second reading. "David, your reading is 0.00 percent which indicates that what we blew before was purely mouth alcohol," says Sergeant Whittaker.
After eating all those truffles, Andrew's breath-test has a reading of 0.00.
So alcohol in a normal meal won't put you over. Dr Worrall says eating solid food slows down the absorption of alcohol into our bloodstream and gives our liver more time to flush it out.
"If you're having a meal of some fairly solid food, like a steak for example, then what the food actually does is keep the alcohol in the stomach longer and if we keep alcohol in the stomach we don't absorb it as quickly," he explains.
But you are ingesting alcohol in the food, so if you add a few glasses of wine you might be in trouble. "If you drink close to your legal limit and then you eat something containing alcohol, then you might push yourself over the legal limit without realising," says Dr Worrall.
If you're eating an alcohol-fuelled meal, think about whether the alcohol has had time to evaporate during the cooking process. If not, it might be a good idea to sit down, have a coffee and let the alcohol get from your mouth down to your stomach. If you have been drinking beer or wine as well, it's best just to get a cab.
If you're tee-total, there are some good alcohol substitutes for cooking. Substitute stock or juice for the wine in the recipe two tablespoons of lemon juice will mimic wine's acidity. In desserts try a dash of balsamic vinegar.