Gelatin is a protein derived from bovine, porcine, or piscine sources and is used as a culinary gelling agent. It is also used as a fining agent in winemaking and brewing. Gelatin is prepared by making a dilute solution in hot water, cooling, and adding a small quantity of the solution to newly fermented beer.
Gelatin fining was once favored by US craft brewers over isinglass because of availability and cost. With advances in centrifugation and filtration technologies, generally only a few smaller brewpub brewers still use gelatin routinely. Gelatin works by the same mechanism as isinglass, although because of its amorphous structure it binds less tightly to yeast than the highly ordered helical structure of isinglass.