Types of Gelatin

Gelatin is sold in several different forms. Granulated gelatin and sheet gelatin are given an initial soaking in cold water so that the solid gelatin network can absorb moisture and dissolve readily when warm liquid is added. If added to the warm liquid directly, the outer layers of the solid granules can become gluey and stick neighboring granules together, though even these clusters eventually disperse. Sheets with their small surface area introduce less air into the liquid, which can be an advantage when the cook wants great clarity in the jelly. There is also an “instant” gelatin that is manufactured by drying the extract rapidly before the gelatin chains can form junctions, so it disperses directly in warm liquid. And hydrolyzed gelatins have been intentionally broken into chains too short to form a gel; they’re used in food manufacturing as an emulsifying agent.