Agar-agar, obtained from certain varieties of seaweed, is another form of setting liquid in a gel form. Its advantages are that it sets more firmly than gelatin and sets at room temperature. It is odorless, tasteless and colorless and is used in kosher, vegetarian and vegan cooking. It is mostly available in health stores and Asian supermarkets.
1 tablespoon/15 ml agar-agar dissolved in
4 tablespoons/60 ml of hot water will set
2 cups/500 ml liquid.