Agar agar

Whisk it into the liquid while cold, bring it to a full boil, then simmer for 1–2 minutes, stirring, so it dissolves and activates. Pour it into moulds before it starts to set.

As a starting point, use about 2 g of agar agar powder for 250 ml of liquid. Use a little less for a soft set and more for a firm, sliceable jelly; different powders can vary in strength.

No. Agar agar sets as it cools, even at room temperature, and makes a firmer, less wobbly gel than gelatine. It also holds its shape at warmer temperatures, so it will not melt as readily on the table.

Yes, but it is not a direct swap: agar agar sets more firmly and can turn brittle if you use too much. Start with about 2 g of powder for 250 ml of liquid, boil it to activate, and adjust the amount next time if needed.

It is used for fruit jellies, set puddings and firm slices of jelly, including Japanese kanten desserts. It also works in plant-based versions of panna cotta and other desserts that would traditionally use gelatine.

Keep the powder or flakes dry in a tightly closed container, away from steam and moisture. Once prepared, cover the set dessert and keep it in the fridge.

Agar agar is a setting substance extracted from certain red seaweeds. It is sold as powder, flakes or strips; powder dissolves most quickly in cooking.