THE TOP THREE TOFU COAGULANTS
Nigari (magnesium chloride)
Characteristics: Produces slightly sweet flavor; firmer tofu than gypsum yields. Can be taken with water as a health supplement, but the flavor can be very bitter. Nigari comes from the Japanese nigai, which means "bitter."
Availability: Clear liquid nigari is sold at many Japanese markets in small plastic bottles, such as the one below on the left. Purchase crystalline or granulated nigari from online vendors, who may also carry liquid nigari. Check health food stores with macrobiotic sections.
Gypsum (calcium sulfate)
Characteristics: Yields mild-tasting tofu that is slightly more tender than nigari tofu. Adds a significant amount of calcium to tofu.
Availability: Use food-grade gypsum, which is also used in beer making. Home brewing suppliers sell gypsum and it is available online. The gypsum sold at Chinese markets tends to have an odd perfume.
Epsom salts (magnesium sulfate)
Characteristics: Functions like gypsum but the resulting texture is slightly grainy. Can be used to alleviate body aches, exfoliate, and relieve constipation. Soak, drink, or scrub with it.
Availability: Widely available and reasonably priced at drugstores and supermarkets.
TOFU ESSENTIALS: EQUIPMENT
Unless you are planning to make rectangular blocks of tofu, you can get by with basic kitchen equipment to make tofu. Silken tofu and soft tofu pudding are prepared in a variety of containers and no special mold or mold lining cloth is required. However, you'll need the following items to handle the tasks involved.
Blender: A regular countertop blender, not the hand-held immersion kind, renders the soaked beans and water to a silky, thick mixture in no time. A food processor can be used, too.
Cooking Soy Milk
Large Pot: To initially cook the soybean slurry, use a pot with a capacity of about two and a half times the amount of water that will be used. For example, rich soy milk calls for 6 cups of water, so use a 4-quart pot. A 6-quart pot is perfect for a batch of light soy milk. If you double a recipe, remember to use larger pots. A nonstick pot makes cleaning easier.
Smaller Pot: To simmer the strained soy milk, find a pot that holds about 1 quart less than the larger pot. For example, a 3-quart pot is plenty sufficient for a 31/4-cup batch of rich soy milk. A 5-quart pot will accommodate a batch of light soy milk just fine. Again, a nonstick pot helps reduce cleanup.
Wooden Spatula: The shape of the spatula mimics a tofu maker's stirring paddle; its flat edge is perfect for effectively stirring a pot of soy milk, cooling the soy milk, and adding coagulant.
Straining Soy Milk
Large Colander or Mesh Strainer: Choose a colander that is a little bigger than the smaller pot so that it fits inside but extends over the pot's rim by about 1 inch. Or use a sturdy mesh strainer.
Pressing Cloth: Have a large piece of cotton cloth to press the soy milk through--a big square of lightweight unbleached muslin or an oversized non-terry cotton dishtowel.
Pressing Tool: Use a potato masher; clean, empty wine bottle; or quart jar.
Shaping Regular and Firm Tofu
Mold: Use a tofu pressing box made of wood or plastic, Japanese bamboo colander (zaru), or a small colander. You can fashion a mold from two disposable aluminum loaf pans. Use the tip of a paring knife to perforate the bottom and sides of one pan with holes, spaced about 1 inch apart, for drainage; employ the other to weight down the curds.
For beautiful, neat block tofu, purchase a dedicated mold. Search online for "tofu kit" and "tofu box." Plastic molds, such as the Soya Joy (the wooden option is pictured on page 21), are great for beginners and are what I provided to my recipe testers; it works well for a batch of tofu made from 6 ounces of dried soybeans. Wooden ones are larger and have a removable bottom for easy unmolding. The one I often use has an opening that spans 4 inches wide, 53/4 inches long, and a scant 31/2 inches deep. The larger wooden mold measuring 43/4 inches wide, 63/4 inches long, and 33/4 inches deep is good for tofu made from 12 ounces of dried beans. Japanese wooden molds, such as the Mitoku, are pricey but beautifully constructed and worth owning if you regularly make tofu.
Mold-Liner Cloth: Use the fabric that came with the purchased mold or a piece of lightweight fabric, such as cotton voile or unbleached muslin; trim the fabric to a size roughly three times the length and width of your mold.
Tofu shortcuts: Canned soybeans, soy flour or purchased soy milk?
With all the soaking, grinding, and cooking involved in making tofu, are there any time-saving shortcuts? Canned soybeans have been cooked, so they won't work. Reconstituting soy flour to make soy milk only saves on the initial soaking time as you still have to strain and cook it twice. Regular blocks of tofu made from soy flour are unpleasantly grainy. Mass-marketed soy milks sold in boxes and cartons do not coagulate well.
The most viable tofu making shortcut is to purchase freshly made soy milk from an Asian grocery store or artisanal tofu shop. Look for 1- or 2-quart plastic containers in the refrigerated section with the dairy products.
If the soy milk is as thick as regular whole milk, it is like medium soy milk and is great for tofu pudding (page 30). It will work for block tofu but you may need to add extra coagulant because there is more fat and protein in this richer milk; your yield will be higher than normal.
Most fresh soy milk has a richness that's akin to lowfat milk, which works perfectly for block tofu (page 32) but not for tofu pudding. Let 8 cups of the soy milk come to room temperature, then bring it to a strong simmer in a large pot. Turn off the heat and stir for about 1 minute to cool to about 170 degrees F; because you don't simmer the soy milk for long, it doesn't get as hot as the scratch method. Then add the coagulant as directed in step 3 of the block tofu recipe. The rest is the same.
Do your best to find organic soy milk with no flavoring. This semihomemade approach is good for beginners and experimenters who want to practice or tinker. For the ultimate quality control, make soy milk yourself.
(More: Lynne Rossetto Kasper's interview with Andrea Nguyen; Nguyen's recipes for Silken Tofu and Silken Tofu and Edamame Soup)