Carrageenan

Carrageenan, like agar, is extracted from a red seaweed (Chondrus). Pastry chefs are generally less familiar with carrageenan than with agar, but it is used in many commercial food products for thickening and gelling. It is particularly effective when used in milk products, which is why it is added to eggnog, chocolate milk, ice cream, and instant flan mixes. In another form, carrageenan is called Irish moss. Irish moss is popular in the Caribbean for thickening beverages and as an aphrodisiac.