Soy Custard

[Sussan Estela Olaya]

Hi Sahmini.

Welcome to the Scoolinary community!

Iota (iota carrageenan) is a natural gelling agent derived from red algae. It’s known for forming soft, elastic gels in the presence of calcium, making it ideal for preparations like custards where a creamy, cuttable—but not brittle—texture is desired.

Can iota be substituted or omitted?

1. Omitting it completely is not recommended if you want to maintain a firm texture that can be unmolded or served in a glass without being too liquid. Without iota, the mixture will be more like a thickened drink and won’t set into a custard.

2. Possible substitutes:

Agar agar: A plant-based gelling agent that produces a firmer, more brittle gel. If used, the dose needs to be adjusted (about 1 g of agar per 300 ml of liquid) and must be boiled for 1–2 minutes to activate it.

Locust bean gum combined with xanthan gum: This combo can somewhat replicate the elasticity of iota, though it’s trickier to work with and less stable.

Starches (such as cornstarch): You can make a more traditional thick custard using about 15–20 g of cornstarch per 300 ml of soy milk. The result will be more like pastry cream, not a gelled custard as with iota.

In summary:

If you’re aiming for a firm, elastic texture, it’s best to stick with iota.

Omitting it without a replacement is not advised, as the dessert will lose its structure.

Hope this helps!

Best regards.