While the assumption is that alcohol will be cooked off, there are other factors that need to be considered. The amount of wine used in cooking is one of them; the more wine used, the longer it takes to cook in order for alcohol to be dissipated. Another point to consider would be, the method of cooking - since alcohol evaporates at around 78degC, simmering and boiling should be hot enough for alcohol to evaporate. However, recent studies have shown that not all alcohol will be cooked off: http://www.todayifoundout.com/index.php/2011/11/alcohol-doesnt-really-cook-out-of-food-in-most-cases/ If you are breastfeeding, it is recommended to breastfeed 2 to 3 hours after consumption of alcohol or foods cooked with alcohol just to be safe.
Read the other answers and they are a little wrong. The truth is it depends on how much Alcohol, how long and the method of cooking. Some alcohol evaporates when cooked. But not all. It takes 2.5 hours of boiling for about 95% of alcohol to evaporate from your food. Simmering a dish for five to 10 minutes won’t do much to the wine, beer, or other spirits used in the recipe; neither will setting the entire dish on fire. But if you commit to cooking recipes for hours at a time, you can preserve the delicious flavor of alcoholic enhancement without the buzz.
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