Carrageenan

A natural carbohydrate derived from Irish moss, carrageenan is widely used in the food industry as a thickening agent. My experience is that, tablespoon for tablespoon, carrageenan powder has about twice the thickening and gelling power of powdered agar. It also produces a slightly more gelatinous, rather than firm, texture. Unlike mixtures made with agar, which don’t melt once they have set, those made with carrageenan will return to a liquid state when exposed to heat. Therefore, carrageenan is a better choice for making cheeses that melt. It is available online (see Resources). Be sure to purchase kappa carrageenan, rather than iota, which produces softer gels, or lambda, which doesn’t have gelling properties.