Beer and Alcohol Burn-Off
The premise that all the alcohol cooks out of the dish during the cooking process is not necessarily a true one.
Alcohol is indeed sensitive to heat, and the longer the dish cooks and the higher the cooking temperature, the less alcohol in the finished product. For example, take a look at this chart compiled by the U.S. Department of Agriculture using wine as an example. Keep in mind that wine has a higher alcohol content than beer, and the chart shows percentages of percentages.