Tofu (Japanese spelling) and doufu (Chinese spelling) share the exact literal translations of bean curd.
Tofu originated in Northern China around 164 B.C.E by Lord Liu An of the Han Dynasty, who coagulated soy milk and then pressed the resulting curds into blocks. The process of tofu was introduced in Japan in the 8th century and spread throughout East Asia, where it became a core ingredient of many cuisines. Many confuse tofu with tempeh, which is both made from soybeans. The difference is that tempeh is made from whole fermented soybeans pressed together and does have a higher protein count than tofu.
Tofu is low in calories, has no saturated fats or cholesterol, is high in protein and omega fatty acids, and contains iron, calcium, and magnesium. Additionally, it contains isoflavones, which can mimic natural human estrogen, which is beneficial for menopause and supports low estrogen levels. Caution should be taken if you have high estrogen levels. Because of tofu’s dry and heavy actions, it can cause gas bloating and sluggishness.
From an Ayurvedic point of view, it is made up of the air and earth elements, has an astringent taste, and is cold, dry, heavy, dull, and tamasic in nature. It balances the Pitta dosha but can drive Vata and Kapha out of balance. Its bio-medical actions include diuretic, anti-inflammatory, nutritive, uterine tonic, constipating, anti-cholesterol, estrogenic, and immunomodulator.
The production of tofu is similar to the production of cheese. Coagulating soy milk is accomplished with coagulants, either salts, acids, or enzymes. Manufacturers combine these coagulants to produce the desired textures, firmness and consistencies, and pore sizes. The most common types of tofu are Soft/silken, which has the texture of custard. Firm tofu is drained with some moisture. Extra-firm has the least moisture, is rubbery in texture, and is easy to marinate. Finally, you can find processed types that were made initially before the days of refrigeration, and today, you can easily find marinated, baked, and smoked.
Many people ask me how I use it in my cooking because it is challenging to get flavor infused. I like to use firm tofu, which I drain, marinate overnight, and then bake in the oven before adding it to recipes.
Jeff's Preparation of Tofu
1. Cut the block of tofu in half lengthwise and then into six slices, making twelve.
2. Place the twelve pieces flat on a kitchen towel, cover them with another towel, and then place some weight on top to assist in draining. (I use a large plate and a jar on top).
3. After about 20-30 minutes, place the tofu in a sealable container, pour the marinade or vinaigrette over it, and level it for 1-24 hours.
4. Use a non-stick baking pan or oiled aluminum foil. Place the marinated tofu on a slippery surface and bake at 375 degrees for 15 minutes; turn them over and repeat for 15 minutes.