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. See finings.

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. See isinglass. As a result, gelatin is generally less effective as a fining agent than isinglass and is usually only suitable for beers served from vessels that are not disturbed (e.g., cellar tanks). In this application brewers are able to serve a pleasing clarity of beer without the need for costly filtration equipment; thus, gelatin served as a useful tool in establishing visual acceptability of early craft beers in the United States.