What Is Carrageenan?
Carrageenan is a powder that’s extracted from various species of red algae. The red algae are farmed and processed to reach the desired powder consistency. The name ‘Carrageenan’ originated from a town in Southern Ireland called Carrageen, where housewives used to boil seaweeds to make jellies and puddings.
The substance is used to thicken and stabilize solutions. While Iota Carrageenan reacts with the calcium  in milk and cream to form a soft gel, Kappa Carrageenan’s gel is very firm and elastic when combined with products that contain potassium.
Simply, Iota will set when added to cream and milk to make vegetarian panacottas and creams and Kappa will set with fruit based potassium containing products.
The element is also used to make soft and elastic gels which don’t lose their properties when heated, stabilize ice creams, frozen desserts and hot dairy foams. Some chefs even use this product to cover an ingredient with a gel coat for presentation.
Properties of Carrageenan
- Both Iota Carrageenan and Kappa Carrageenan are thermo-reversible. Their gelling/melting temperatures are roughly 40c and 70c.
- Iota forms a soft, gel like structure when it is combined with calcium salts like calcium lactate, calcium chloride etc. Kappa on the other hand forms stiff and brittle gels in the presence of potassium salts. Both can be combined to reach the desired consistency.
- While Iota Carrageenan is stable when thawed or frozen, kappa is not stable.
- Iota is known to provide a melt-in-the-mouth sensation while Kappa’s mouthfeel changes depending on its concentration.