Q. People who sell all kinds of chametz liquors before Pesach to a Non-Jew, why do they abstain from selling beer to them?
A. See question above in regards to avoiding the sale of chometz gomur or certainly and Biblically prohibited chometz. Liquors that were created from fermented grain distillation are indeed a product of the condensation of the vapors of that distillation. Yet they are not chometz gomur, since they are only a condensed by product.
However, beer is not a distillate, it is rather the ferment of the grain itself, and thus should be considered chometz gomur, and when possible not be included in the leniency of the chometz sale.
Horav Shlomo Miller’s opinion is similar.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a