"According to the U.S. Department of Agriculture (USDA), baked or simmered dishes that contain alcohol will retain 40% of the original amount after 15 minutes of cooking, 35% after 30 minutes and 25% after an hour. But theres no point at which all of the alcohol disappears. Baking or simmering an alcohol-containing dish for 2.5 hours will still leave 5% of the alcohol content behind.
Exactly how alcoholic the 40% or 25% or 5% of alcohol leftover in a dish after cooking directly depends on the ABV, the alcohol by volume, of the liquor used. When cooked at the same temperature, for the same period of time, in the same sized pot, the alcohol molecules in beer and rum will evaporate at the same rate. However, beer typically has an ABV that ranges from 3.5% to 9%, while the ABV of rum is typically around 40-75.5%. Consequently, even when all other conditions are the same, the completed dish will be less alcoholic when made with beer than that when made with rum.
Although alcohol remains, its highly unlikely that dishes cooked with alcohol will cause intoxication. The amount of wine, beer, or spirits found in most recipes is so small that, even if left uncooked, an adult would never feel its effects. Still, an alternative might be preferable when preparing food for children, pregnant women or those in recovery. "