Tofu, or bean curd, is made by adding a coagulant to soy milk - the liquid extracted from boiled and crushed soy beans.
After the soy milk separates into curds and whey, the curds are scooped off and then set. They are then pressed and become hard. By the way, the coagulant that's often used is calcium sulfate, or gypsum, which has no taste whatsoever.
Tofu is usually made into blocks about two-inches deep. The bean curd, called "doufu" in China, is often offered in water-packed barrels. It should be refrigerated immediately after being purchased and used within a week.
Tofu is an excellent source of protein with a low fat content (hovering around 5 %). It's fantastic in soups, layered with minced pork or steamed with sauce.
There are many kinds of bean curd and ways of preparing it:
DEEP-FRIED: firmer, pressed tofu is deep-fried in very hot oil until its crisp outside and soft inside. This has an almost nutty flavour and can be refrigerated for weeks. The squares can be cut up and added to broth or braised dishes.
GRILLED: made by grilling both sides of a slightly-pressed bean curd over very high heat. Known in Japanese as "yakidofu." It tends to absorb flavours easily, making it ideal for stews, slow-cooking dishes and soups.
PRESSED: also known as "Tau Kwa," it is available loose or packed in tubs. It's a solid cake of tofu about one-inch thick. Keep sealed and refrigerate and use before the expiry date. It's often fried crisp first and then drained and sliced. Often added to salads, soups, noodles and stir-frys.
SILKEN: the softest type and called "kinugoshidofu" in Japanese. Its fine texture is popular in many Chinese dishes. Made when the curds of the coagulated soy milk are not drained. It can be refrigerated for up to three weeks. Silken tofu can be sliced and steamed or diced and added to soups.
BEAN CURD SKIN: the skin forms top of the vats of boiling soy milk, which is lifted off and dried. The skin has the highest percentage of protein of all soy products. It is used as a meat substitute in Chinese vegetarian plates. They are often added to braised dishes.
TOFU CUSTARD: also known as "Tau Fa," it is served often as a dessert, doused in a sugar syrup that is tinged with almond flavour. The custard can be stored for up to three days in a covered container.
TEMPEH: Made from soaked and boiled soy beans mixed with bacteria, triggering fermentation and moulding. This forms a solid cake. It is one of the few sources of vitamin B12 and popular in vegetarian dishes. Fresh tempeh tends to be white with pale yellow soy beans visible and a taste of a nutty mushroom. Generally sold vacuum-packed in health and Asian stores. Tempeh is often simmered in sauces or soups and stews or deep-fried with crushed garlic, cilantro and salt.
