Tofu with Adjusted Soy Milk – 3 Sodifying Experiments


Now, in this post, I will show you an experiment to solidify different types of soy milk.


Making Bittern

Nigari Ingredients

According to the website of the National Federation of Tofu Associations, the coagulant used is following;

  • Calcium sulfate
  • Magnesium chloride
  • Glucono-delta-lactone
  • Calcium chloride
  • Magnesium sulfate

Of these, the mechanism by which glucono-delta-lactone works as a coagulant is probably different from that of the other four substances. Naturally, the recipes will also differ. When making tofu for the first time, I think it is safe to start with coagulants other than glucono-delta-lactone.

Magnesium sulfate, sold as Epsom salts, is also easy to find, although it is not commonly used in tofu making in Japan.
Pure Epsom Salt (1 lb.), Magnesium Sulfate Soaking Solution, Top Grade
Pure Epsom Salt (1 lb.), Magnesium Sulfate Soaking Solution, Top Grade

How to Make Bittern

Now, dissolve calcium chloride and other salts in water to make bittern. To make bittern, use 1 teaspoon of magnecium chloride in 2 tablespoons of water.
How to Make Bittern - Choice and Amount of Powder Nigari
Bittern, Nigari in Japanese, is essential for making tofu. What type of bittern and how much of bittern should we use? It's easy to find.

If using salt other than magnecium chloride, the same amount is fine.

Solidify the Soy Milk

Now, it’s time to experiment with solidifying soy milk.

To make tofu using non-adjusted soy milk, first heat 250mL of soy milk to just before boiling, add 1 teaspoon of bittern, mix well, and let stand for 30 minutes. If a solid forms after letting it stand and the supernatant is clear, it is considered to have hardened, and the water is drained and the hardening process begins.

Part 1 – Pirkka’s Soy Milk

Since this soy milk does not contain any stabilizers, I expected that it would harden easily even with bittern.

1 teaspoon of bittern

When I heated the soy milk and added 1 teaspoon of bittern, a lumpy white mass formed. Could this make tofu? I let it stand for 30 minutes, hoping that it might make tofu.

After 30 minutes, a small lump had formed, but the whole soy milk was still white, so I decided that it had not fully solidified.

2 teaspoons bittern

I heated the soy milk again and added the bittern. That’s a total of 2 teaspoons of bittern added. Cover with a lid and let it stand for 30 minutes.


After 30 minutes, when I tilt the pot, it has become quite thick. The supernatant is also clear. It has hardened!

Dehydration & Tasting

Place a cloth in a container with holes and pour it into the container to dehydrate.

After 30 minutes, the tofu looks like tofu. The only thing that worries me is that I added double the amount of bittern. Perhaps there may be some bitterness left in the taste.

When I took a bite, there was no bitterness at all. The tofu was quite creamy in the mouth and had a rich flavor. Yes, this is tofu!

Part 2 – Lidl’s Soy Milk

Since this one contains a stabilizer, I expected that it would not solidify without adding a large amount of bittern.

1 teaspoon of bittern

I heated the soy milk, added 1 teaspoon of bittern, and let it stand for 30 minutes, but there was no change.

2 teaspoons of bittern

Heat the soy milk again, add 2 teaspoons of bittern in total, and leave it for 30 minutes.

You can see that there is a film like Yuba on the surface. This soy milk is made from 9.7% soybeans, so it may be usable for making Yuba. However, we are now experimenting with tofu. Two teaspoons is not enough to make it solid yet.

3 teaspoons of bittern

I heated the soy milk again and added a total of 3 teaspoons of bittern. At this point, you can see a fuzzy white lump forming. Let this stand for 30 minutes.

You can see that the grains are much finer than the ones from Pirkka. The supernatant is clear, so we can judge that it has hardened here.

Dehydration & tasting

Place a cloth in a container with holes and pour it into the container to dehydrate. As soon as it is poured out, the water will run out and all that will be left is loose grains.
I’m worried about the taste of this one too, since it uses three times as much bittern. I took a bite, and it tasted like tofu. It is also quite thick. However, it is not smooth and has a lumpy texture.

Since the water drains out quickly, I molded it in a different way. After hardening with bittern, I dehydrated it using a fine colander. Cool the remaining solids in a mug or other container. This is the only way to make it look like slightly coarse firm tofu.
Homemade Hard Firm Tofu with Stabilized Soy Milk
Tofu can be made using commercial soy milk. This recipe is for hard firm tofu made from soy milk with the following ingredients: water, soybeans, and stabilizer.

Part 3 – alpro’s soy milk

This one contains a pH adjuster. I expected that it would be difficult to solidify soy milk, since the pH needs to be lowered in order for it to solidify.

I added a lot of bittern

When I added 4 teaspoons of bittern, fine grains started to form. However, after adding more bittern, there was no sign of precipitation, so I added about half a teaspoon of calcium chloride. No matter how much I added, there was no precipitation.

When I observed carefully, I found that many very fine grains had formed and were dispersed. When I looked at the supernatant only, it was clear, so it must have solidified at some point.

I tried to dehydrate it to test it, but the grains were so small and did not seem to connect with each other even after a few hours, so I decided that alpro’s soy milk was not suitable for tofu making.

How to Solidify Soy Milk

The results of the experiment alone were quite extensive. In the next post, I will share what I learned from the experiment, tips on choosing soy milk, and a recipe for making tofu with adjusted soy milk.
Homemade Firm Tofu Recipe Choice of Soy Milk
Are you interested in homemade tofu? Is it possible to make tofu using store-bought soy milk outside of Japan? I searched it and did trials.


  1. Valerie says:

    I found your website while looking for guides to umeshu and came across this helpful post! I’m living overseas (in the UK) and have tried to make tofu with the store-bought soy milk before, but I bought Alpro…thank you for explaining why it didn’t work, now I know what to look out for if I ever try again! Thank you for this post!!

  2. Hi, thank you for your comment! I’m very happy to help you with my curiosity for foods:)

    Actually, it’s so difficult to make perfect tofu using soy milk sold in abroad. But we can make something similar. I hope you would enjoy the tofu including the difference:)

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