Now that I am armed with ideas of how to keep my rising bread warm (thanks Chowhounds!), I want to find a use for some leftover beer and thought I would make beer bread. Most of the recipes I have found say to use flat beer and I can do that but am curious as to why. I'm not a beer drinker so, my beer knowledge is quite limited. I presume I just open the can and let it sit around awhile?