E404 Calcium alginate (Seaweed salt)

E404Thickeners & gumsOrigin: Plant

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VeganYes

Gluten-freeYes

HalalYes

KosherYes

KetoYes

Low-FODMAPYes

Seaweed fiber that is not considered a high-FODMAP problem at normal amounts.

The short answer

Calcium alginate (E404) is a seaweed-based gel that sets in cold liquid when it meets calcium. It's the basis of vegan spheres and cheese analogues. It's vegan, gluten-free and safe.

90/100

Generally safe

Fine for most people at normal amounts.

E-numberE404

Comes fromPlant

What it doesThickeners & gums

Glycemic index—

Daily limitNot set

Also calledAlginate of calcium, Calcium salt of alginic acid

Rules by country

🇺🇸 US FDAApproved

🇪🇺 European UnionApproved

🇨🇦 Health CanadaApproved

CaliforniaNo extra rules

Approved in the US, EU and Canada as a stabilizer and gelling agent. Alginates are among the most widely used seaweed extracts in food.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

Alginic acid is a fiber from brown seaweed. When it meets calcium ions, the chains lock together into a gel. Chefs use this to make soft spheres and vegan cheese, and food makers use it to set fillings and stabilize texture.

Where it comes from: Alginic acid comes from brown seaweed. Calcium is added to make an insoluble salt that forms a gel without heat.

Why it’s in food

Sets fruit fillings and jellies without gelatin
Makes vegan cheese and cream stretch
Holds meat analogues together
Makes soft, liquid-filled spheres

Often found in

Vegan cheeseFruit fillingsBubble tea pearlsMeat substitutesDessert gels

Also listed as: Alginate of calcium, Calcium salt of alginic acid, E404

Health & gut impact

FiberBenefit

Like other seaweed fibers, it passes through the gut mostly undigested and adds a little to daily fiber intake.

EFSA Panel on Food Additives (2017)

Making spheres or vegan cheese? Start with the right gelling salt

For your pantry

Culinary grade

Food-grade sodium alginate powder

The base ingredient for calcium-set spheres and gels.

Shop sodium alginate Opens your country’s Amazon store

Setting bath

Calcium lactate for spherification

Dissolves cleanly and sets the alginate without a chalky taste.

Shop calcium lactate Opens your country’s Amazon store

Vegan gel

Plant-based gelling kit

A starter set for vegan cheese and gel experiments.

Shop vegan gelling kit Opens your country’s Amazon store

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What can I use instead?

Agar-agar

Ratio: 1 tsp per 1 cup liquid

Best for: Heat-set jellies

More thickeners & gums:

Agar-Agar E406Agar-agar (E406) is a seaweed gel that sets firmer than gelatin. It's safe, vegan, gluten-free, keto and kosher, and is the easiest plant swap for gelatin.Generally safe Carrageenan E407Carrageenan (E407) is a seaweed thickener in plant milks and deli meats. It's approved, but some studies link it to gut inflammation, so people with IBD often avoid it.Use in moderation Cassia gum E427Cassia gum (E427) is a seed thickener, not cinnamon. Europe allows it in limited foods. In the US it is mainly a pet-food ingredient. Specs are strict because early batches carried impurities.Use in moderation Cellulose Gum (CMC) E466Cellulose gum (E466, CMC) is a thickener made from wood or cotton fiber. It's approved everywhere and fine for most diets, but studies in mice and a small human trial suggest it can disturb gut bacteria.Use in moderation

Common questions

Is calcium alginate vegan?

Yes. It is made from seaweed and mineral salts, with no animal ingredients.

Why does calcium alginate make spheres?

Calcium ions link alginate chains into a thin gel skin, so a drop of liquid sets into a sphere.

Is Calcium alginate safe?

Generally safe (90/100). Approved in the US, EU and Canada as a stabilizer and gelling agent. Alginates are among the most widely used seaweed extracts in food.

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Scientific sources & regulatory citations

EFSA OpenFoodTox: E404
EFSA Panel on Food Additives (2017)

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