Agar-Agar

The agar-agar technique is the use of agar-agar, a powerful plant-based setting agent from red seaweed, to create gels, jellies, foams, and films. It is one of the favourite tools of molecular cuisine and at the same time a traditional gelling agent of Asian cookery and a vegetarian alternative to gelatine.

The chief peculiarity of agar is its unique behaviour with temperature. It is dissolved by bringing the liquid to the boil (about 90–100 °C), yet the gel sets already at 35–40 °C, that is at room temperature, without chilling in the refrigerator. The finished jelly is heat-stable: it does not melt in the hand and holds its shape even in warmth, until it is reheated to about 85 °C. Compared with gelatine, agar gels are firmer, more “brittle”, and give a clean, transparent cut. In molecular cuisine agar is used for hot jelly, thin springy strips, “spaghetti” of juices, the stabilising of foams, and as a base for the fluid gel technique, when the set mass is blitzed with a blender to a creamy texture.