Also known as ‘agar-agar’ (the Malay term for jelly), agar is a substance derived from seaweed, and a useful vegetarian alternative to gelatin. It can be used to thicken soups, to make jellies (it’s especially popular in Japanese desserts), and as a clarifying agent for brewing. You might also have heard of it as the stuff that bacteria is grown on in petri dishes.
It’s most commonly available as flakes or powder, which form a firm, clear, mostly flavourless jelly when mixed with water. You can buy it in Waitrose, in the home baking section, or online from Wing Yip. Just don’t eat it straight from the petri dish.
Here's a general guide on how to use agar in recipes:
• Substitute powdered agar for gelatin using equal amounts.
• 1 tbsp of agar flakes is equal to 1 tsp of agar powder.
• Acidic ingredients, such as lemons and strawberries, may require more agar to be added. Also, some fresh fruits – mangoes, papaya, and pineapple – contain enzymes that break down the agar, so that it will not set. Cooking these fruits before adding them to a recipe destroys these enzymes, allowing the agar to set as normal.