Carrageenan

What it is

A family of gelling/thickening polysaccharides from red seaweed (notably Irish moss, Chondrus crispus). Vegan, gluten-free.

How it's made

Seaweed is extracted (alkali-processed) to yield three functional types: kappa (firm, brittle gel, especially with potassium), iota (soft, elastic gel, especially with calcium), and lambda (non-gelling; thickens only).

Flavor profile

Neutral; chosen for the kind of set or thickening it gives.

Culinary uses & behavior — Softer and more elastic-setting than agar, and famously reactive with dairy proteins, which is why it's the classic thickener/stabilizer in chocolate milk, ice cream, processed dairy, and non-dairy milks (it suspends cocoa and prevents separation). Traditionally, Irish moss itself is simmered into milk to set carrageen moss pudding (a silky Irish blancmange-like dessert). Modernist cooks use kappa/iota for elastic gels and fluid gels. It can do soft, dairy-compatible sets and stabilizing; pure lambda only thickens, won't gel.

Regional variations

Irish (carrageen moss pudding), and a global food-industry stabilizer; gulaman in the Philippines overlaps with agar in usage.

Cultural & historical context

Named for Carragheen on the Irish coast, where harvesting Irish moss and setting it into milk puddings is a centuries-old folk tradition (and a famine food). It traveled from that humble origin to become one of the most widely used industrial food additives in the world.

Reference notes

Tags: `hydrocolloid`, `seaweed`, `vegan`, `gluten-free`, `gelling-agent`, `dairy-reactive`, `stabilizer`. Related ingredients: [Agar-Agar], [Gelatin], [Guar Gum]. Related cuisines: Irish, modern food industry. Suggested links: → Carrageen moss pudding, → Agar-Agar, → Hydrocolloids.