Substituting Agar Agar for Gelatin

Is agar agar a substitute for gelatin in recipes?

Is agar agar a substitute for gelatin in recipes?

Agar agar, like gelatin, thickens recipes. It’s a complex polysaccharide (carbohydrate) made from red seaweed, so it's OK for vegetarians to eat. Gelatin, which is made from the tissue and bones of animals, is not. Unlike more consistent gelatin, agar agar comes in flakes or powder and may vary in strength from brand to brand.

We tested the Eden brand of agar agar sea vegetable flakes (the only one carried by our local supermarkets; natural foods stores typically carry several brands) and found that ³⁄4 teaspoon of the flakes firmed a cup of water to the same consistency as a level teaspoon of gelatin did. However, to fully dissolve the agar agar, we needed to soak the flakes in the water for 10 minutes, then boil the mixture for another 10 minutes. We also tested the flakes in our Icebox Key Lime Pie and Peanut Butter Icebox Cheesecake, with mixed results. We were able to dissolve the agar agar in the lime juice called for in the pie but not in the heavy cream in the cheesecake; the finished cake was a loose, liquidy mess.

THE BOTTOM LINE Agar agar thickens liquids at about the same ratios as gelatin, but requires more liquid and more time to dissolve. Agar agar won’t thicken cream or milk-based liquids.

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