Tofu, or bean curd, is a product made by coagulating soy milk and then pressing the resulting solids to remove moisture. Tofu has been a part of Chinese cuisine for thousands of years and is now widely consumed around the world. Tofu's neutral flavor and variety of textures make it easy to add to any dish.
How is Tofu Made?
Soy milk, which is a suspension of soy derived fat and protein in water can be coagulated to separate the solids from the liquid, very much like dairy milk is coagulated to make cheese. Once the soy milk is coagulated, the mixture is pressed into a block to remove some moisture, leaving the semi-solid tofu behind.
Several different substances are used to coagulate soy milk, each producing a different texture in the final product. Salts, such as calcium sulfate, calcium chloride, and magnesium chloride produce a tender-firm tofu and can provide additional dietary calcium. Acid coagulants, like glucono delta-lactone produce a soft-jelly like tofu that is often labeled "silken tofu." Enzyme coagulants, such as papain, are not widely used for commercial tofu production, but manufacturers are exploring enzymatic coagulants more than ever in recent years.
Once the soy milk is coagulated, the resulting curd is pressed and shaped using different methods depending on the type of tofu produced. The firmness of the tofu is often dependent on the amount of moisture removed during this step.
Silken Tofu - Silken, or "soft" tofu has the highest water content of tofu varieties and has a jelly or custard-like texture.
Firm Tofu - Although firm tofu still has a high amount of moisture, it is firm enough to hold its shape. Some describe the texture of firm tofu to that of raw meat. Firm tofu can easily be sliced and grilled, baked, fried, or steamed.
Extra Firm Tofu - Extra firm tofu has had a large amount of moisture removed and can therefore be shredded or even crumbled before adding to dishes. It has a somewhat rubbery texture, similar to that of dairy cheese.
Fermented Tofu - Sometimes referred to as "stinky tofu," this variety of tofu is fermented in a brine. Originally a method of preserving tofu, fermenting tofu is now prized for its flavor and texture.
Flavored Tofus - Most tofu is flavored using sauces or marinades before cooking, but flavor can also be added prior to the curdling step. Sweet tofus often have fruit and a sweetener added to them and are perfect for use in desserts. Savory flavor options include egg or soy sauce flavored tofus.