Burping is often due to H.
pylori infection of stomach. This is very likely in your case, since
Protonix helped your pain - which is from acid, bur not burping, which is from gas produced by H. pylori bacteria. Have a breath test, if positive, you get antibiotics for H. pylori.
Beer contains maltose, and when bacteria ingest it, produce a lot of gas. The same, in lesser extent, may happen with other alcohol, and also with sugar.