Gelatin

Gelatin must be bloomed before use: powder is sprinkled over cold water and sheets are soaked until soft, then the gelatin is dissolved in warm liquid. Boiling weakens it. One standard envelope of powder, about 1/4 ounce (7 g), sets roughly 2 cups of liquid to a soft gel.

It is the backbone of panna cotta, mousses, Bavarian cream, marshmallows and stabilized whipped cream. Fresh pineapple, kiwi and papaya contain enzymes that stop gelatin from setting unless the fruit is cooked first. Agar is a plant-based setting agent that behaves differently.