Nigari vs gypsum: which tofu brands use which, and what changes

Nigari is magnesium chloride drawn from seawater, and it is vegan. It is one of the two salts that turn soy milk into tofu; the other is gypsum, which is calcium sulfate. Which one your block used is on the ingredient list, and for the biggest US brands the answer is both.

The label settles an argument the internet keeps having. Nasoya’s organic firm and extra firm blocks list calcium sulfate and magnesium chloride together, and so does Wildwood’s organic sprouted firm. House Foods uses calcium sulfate alone in its firm block, adds calcium chloride for extra firm, and switches to magnesium chloride for silken. Mori-Nu’s shelf-stable silken uses neither. So for most blocks the shelf will not answer “nigari or gypsum” with one word. What each salt does is answerable, and the one place you will see a difference you can measure is the calcium line, covered below. If you have never read a tofu label past the soybeans, our guide to whether tofu is plant-based starts further back.

What nigari is

Nigari is the Japanese name for bittern, the liquid left after salt crystallizes out of evaporating seawater. The USDA’s 1999 technical review of magnesium chloride for organic handling describes magnesium chloride “extracted from seawater, known commonly as ‘nigari’ or ‘bittern'”, and says the mixture of magnesium chloride and magnesium sulfate that results is traditionally called nigari. The same review lists seawater, natural brines and the potash industry as sources, recovered by solar evaporation and then crystallizing out the other salts.

That is the mineral in the bag. It is also a food additive with a federal definition: 21 CFR 184.1426 lists magnesium chloride as generally recognized as safe, with no limit on use beyond good manufacturing practice, and describes the lab route of dissolving magnesium oxide, hydroxide or carbonate in hydrochloric acid. Both routes end at the same molecule. The organic review draws the line between them: evaporated from salt water or brine counts as non-synthetic, the acid route does not. A bag that says “nigari” is telling you the seawater story; a label that says “magnesium chloride” is telling you the molecule and nothing about where it came from.

On vegan status there is nothing to argue about. Magnesium chloride is a mineral salt, the Vegetarian Resource Group classes nigari as vegan, and when it asked producers, Mitoku answered that its nigari “does not contain any animal/animal derived ingredients/processing aids”. Gypsum is the same story from the other direction: calcium sulfate, a naturally occurring mineral the FDA lists as GRAS, with firming agent and nutrient supplement among its permitted uses.

Nigari or gypsum: what actually changes

Texture, a little, and calcium, a lot.

On texture, the old version of this page said nigari makes firmer tofu. The USDA review says the opposite, citing a 1997 study: of the two coagulants suited to Chinese-style tofu, “calcium sulfate tofu is both harder and more brittle than nigari tofu”. The review also lists calcium chloride and glucono delta-lactone as the other coagulants, each giving a different texture again. House Foods sells firm, extra firm and super firm blocks from the same two salts, so the firmness word on the front is not telling you which coagulant is inside.

Calcium is where the coagulant shows up in a number. USDA’s SR Legacy tables carry tofu entries by coagulant, per 100 g:

USDA entry	Calcium, mg	Magnesium, mg	Protein, g
Tofu, raw, firm, prepared with calcium sulfate	683	58	17.3
Tofu, raw, regular, prepared with calcium sulfate	350	30	8.1
Tofu, hard, prepared with nigari	345	53	12.7
Tofu, extra firm, prepared with nigari	282	35	10.0
Tofu, firm, prepared with calcium sulfate and magnesium chloride (nigari)	201	37	9.0
Tofu, soft, prepared with calcium sulfate and magnesium chloride (nigari)	111	27	7.2

Read the rows alongside the protein column. The firm calcium sulfate entry is also the densest block on the list, 17.3 g of protein per 100 g against 10 g for the extra firm nigari one, so the rows are not like for like. Even so, the two entries closest in protein, hard nigari at 12.7 g and firm calcium sulfate at 17.3 g, sit at 345 and 683 mg of calcium. The coagulant is the salt the calcium came in with. If calcium is why you buy tofu, read the nutrition panel on the block you are holding; the ingredient list tells you which salt, the panel tells you how much ended up in it.

The products, one by one

Two bags of nigari you can buy in the US and five tofu brands, read from their own pages. Prices are the sellers’ own, as of October 2026, and change.

Handy Pantry Japanese Nigari Tofu Coagulant (True Leaf Market)

Dried, refined Japanese nigari, sold by True Leaf Market under its Handy Pantry label in 12 oz ($10.86) and 24 oz ($19.89) bags. The listing gives the only per-batch dose on this page: dissolve 2 teaspoons in about half a cup of hot water, stir into 2 quarts of hot soy milk, stand 15 minutes, then into the mold, for a little over a pound of tofu. It also says a 12 oz bag makes “well over 75 lbs of tofu” in one place and that each pound makes over 100 lbs in another; those two figures do not agree with each other, so treat the yield as a lot and the dose as the number that matters. Both sizes showed as sold out when we read the page. Do not buy a 24 oz bag for a hobby; at 2 teaspoons a batch you will be handing it down.

Sanlinx Natural Nigari (Soymilkmaker.com)

An 8 oz zip bag of fine-granule magnesium chloride at $9.99, sold by Sanlinx, the SoyaJoy soy milk maker company. The page says it will coagulate about 120 lb of tofu, gives no per-batch dose, and sources it from the Cha’erhan salt lake in the Qinghai-Tibet highlands, 8,000 feet up. The same page opens by calling it “ocean nigari”, which a salt lake at altitude is not. It is still magnesium chloride and still a brine evaporate, so for tofu it does the same job; it just is not the seawater nigari the word usually promises. There is no vegan statement on the page, and none is needed for a mineral salt, but if you want the maker to say it, this one does not.

Nasoya Organic Firm and Extra Firm Tofu

Water, organic soybeans, less than 2% of calcium sulfate and magnesium chloride, with soy declared as the allergen, on both the firm and the extra firm block. The brand’s own pages describe the ingredients as “water and organic, whole soybeans” and leave the salts to the panel. Nasoya calls itself America’s number one tofu brand, which means the tofu most Americans eat is a nigari and gypsum blend whether they know it or not. If you want one coagulant on its own, this is not the brand.

House Foods Premium Tofu: Firm, Extra Firm and Silken

The one brand that uses a different salt per texture. Premium Firm is water, soybeans and calcium sulfate; Premium Extra Firm adds calcium chloride; the silken block is water, soybeans and 1% or less of magnesium chloride and glucono delta-lactone. Its organic line follows the same pattern, calcium sulfate for firm and calcium sulfate with calcium chloride for super firm. So House Foods is the brand to buy if you want to taste the difference yourself: a gypsum block and a nigari block from one maker, same beans, same day. The catch is that the nigari one is silken, so you are also comparing a pressed block with an unpressed one.

Hodo Organic Extra Firm Tofu

Hodo is the gypsum purist of the set: water, organic soybeans and calcium sulfate, which its page calls “a naturally occurring mineral”, in 3 oz servings, about 3 per pack. If you had assumed a dense artisan block meant nigari, the label says otherwise. Not the block for anyone chasing the lowest-calcium entry on the USDA table, since the gypsum rows sit at the top of it; that is a feature for most people.

Wildwood Organic SprouTofu Firm

The sprouted beans are the point of difference here, not the coagulant. The list is water, organic soybeans, 2% or less of calcium sulfate and magnesium chloride, soy declared, which is the same blend Nasoya uses. Buy it for the sprouting if that matters to you; anyone expecting a nigari-only block will be reading the same two salts as everywhere else.

Mori-Nu Silken Firm Tofu

Water, soybeans, soy protein isolate, glucono-delta-lactone and calcium chloride. No nigari, no gypsum. It is the box Mori-Nu sells as shelf stable, and its coagulant is one the USDA review lists as giving a texture different from both of the traditional salts. If the question you came here with was nigari or gypsum, this box’s answer is neither, and that is fine for a smoothie or a dessert and wrong for anything you wanted to press.

Buying nigari and using it

Buy the smallest bag. Handy Pantry’s dose of 2 teaspoons per 2 quarts of soy milk means even an 8 oz bag outlasts most people’s interest in making tofu, and Sanlinx’s own 120 lb estimate for 8 oz says the same thing in a different unit. Check the bag for the word “nigari” or “magnesium chloride” and, if origin matters to you, for where the brine came from, because the two bags above come from Japan and from a Tibetan salt lake respectively. Keep it dry; the FDA’s own description of magnesium chloride is of a deliquescent crystal, which is the regulatory way of saying it pulls water out of the air and turns to syrup if you leave the bag open.

Once the block is made, or bought, the next question is what to do with it, and our guide to microwaving tofu covers the fastest answer.