© Denzil Green
To make Tofu, soy beans are soaked for up to 8 hours in water. Then they are ground in the water (making soy milk, basically), and the mixture is heated until it reaches 212 F (100 C.) It is then let cool, at which point a mineral coagulant is added.
The mineral used can be calcium sulfate, or magnesium chloride. The Chinese prefer the calcium sulfate (calcium salt), which they mine. The Japanese use magnesium chloride; it is contained in the mineral-rich liquid that remains after sea salt is extracted from sea water, which they call nigari. It is this liquid that they use.
The coagulant does for soy milk what rennet does for cheese, which is make it curdle.
It takes about two hours for the curds to form. Then the curds are gathered, pressed to squeeze the whey out of them, and formed into blocks. (Silken Tofu, however, is not pressed.)
Tofu has no particular taste on its own. It will take on the taste of what you cook or season it with.
Leclaire & Schenk
Before using Tofu, drain it well.
One suggested way to drain it is by placing the Tofu on paper towel, then putting some paper towel on top of it, and weighing that paper towel down with a plate.
Let stand like this for about 15 minutes.
The different Tofus have quite different nutritional values.
- Firm Tofu: 120 calories, 13g protein, 3g carbohydrate, 6g fat, 9mg sodium, 120mg calcium, 8mg iron, 0 cholesterol
- Soft Tofu: 86 calories, 9g protein, 2g carbohydrate, 5g fat, 8mg sodium, 130mg calcium, 7mg iron, 0 cholesterol
- Silken Tofu: 72 calories, 9.6g protein, 3.2g carbohydrate, 2.4g fat, 30mg sodium, 40mg calcium, 1mg iron, 0 cholesterol
1 pound firm Tofu = 450g = 2 ½ cups cubed or 2 cups crumbed or 1 ¾ cups puréed
1 pound soft Tofu = 450g = 1 ¾ cups puréed
Fresh Tofu will keep for up to a week.
Store Tofu refrigerated in water, changing the water daily.
You can also freeze Tofu for up to 3 months, but it will be chewier after it has been frozen.