Comparison
Agar or carrageenan.
Both come from red seaweed and they are not substitutes. Agar makes a firm brittle gel that melts at a high temperature. Carrageenan makes softer gels and interacts with milk proteins, which is why dairy uses it and confectionery uses agar.
Side by side.
| Criterion | Agar | Carrageenan |
|---|---|---|
| Gel character | Firm and brittle, cutting cleanly. What jelly confectionery and laboratory media need. | Ranges from soft elastic to firm depending on the type. Kappa, iota and lambda behave very differently. |
| Melting temperature | High, so the gel holds at warm ambient temperatures. This is agar's distinguishing property. | Lower. Gels soften and melt at temperatures agar would ignore. |
| Dairy | Does not interact usefully with milk proteins. | Reacts with casein, which is why it stabilises dairy drinks and why it dominates that application. |
| Dosage | Very low use levels for a firm gel, which offsets the higher price per kilo. | Higher use levels typically, and cheaper per kilo. |
| Raw material | Gracilaria, mostly pond farmed in Indonesia. | Eucheuma and Kappaphycus, farmed on lines in shallow coastal water. |
| What it is bought on | Gel strength, measured under stated conditions. | Type, viscosity and gel behaviour. Naming the type matters more than any single number. |
Which to choose.
- You are making jelly confectionery
- Agar, specified on gel strength.
- You are stabilising a dairy drink
- Carrageenan, and name the type.
- The gel must survive a warm room
- Agar. The high melting temperature is the reason to pay for it.
- You want a vegetarian gelatine replacement
- Agar for firm applications. Neither behaves exactly like gelatine, so reformulate rather than substitute.
Read next.
Questions buyers ask.
Can I swap one for the other?
Not directly. They gel differently, melt at different temperatures and behave differently with protein, so a formulation has to be redeveloped rather than the ingredient exchanged.
Which is cheaper in use?
It depends on dosage rather than on price per kilo. Agar costs more per kilo and is used at much lower levels, so compare cost per unit of finished product.
Are both vegetarian?
Yes, both are seaweed derived, which is why they appear as gelatine alternatives. Any claim on your pack still has to satisfy your own market's rules.
Still deciding?
Tell us the application and the market. We will say which one your specification actually needs, and quote both if it is genuinely close.