Are you brewing? If so, you simply don't add yeast; or only let it ferment for an hour or two to create an NA..
I assume, though, you're referring to packaged beer. In this c…ase, the only good way to do it is to boil the beer. Boiling alcoholic beverages, or cooking with them, removes the alcohol (it is steamed, boiled, or cooked away). The problem is the carbonation. When you put the flame to the pot of beer, CO2 will begin to rapidly release, most likely causing a boilover. In order to avoid this, you'll want to de-carbonate the beer first by leaving it at room temperature in an open pot or pan (leave a thin covering of cheesecloth or wax paper to prevent anything from falling into it - but it can't be airtight). After a few hours, the beer's CO2 will have evaporated to the point where boiling won't be an issue..
Here's the problem... when you're finished boiling, you're left with a hot, flat, non-alcoholic beer....
Doesn't sound too tasty to me. ( Full Answer )