Vegetable bean curd, also known as tofu, is a food made by coagulating soy milk and then pressing the resulting curds into solid white blocks. Tofu is a staple in East Asian cuisines and has become popular in Western cuisine as a plant-based protein source. Some key facts about vegetable bean curd:
- Tofu is made from soybeans. The beans are soaked, ground, boiled, and strained to produce soy milk.
- Coagulants like calcium sulfate or magnesium chloride are added to the soy milk to cause it to curdle and separate into curds and whey.
- The curds are pressed to create a solid block, which becomes the tofu.
- Tofu can be firm, soft, or silken depending on how much it is pressed.
- It is a good source of plant-based protein, providing around 8-10 grams per 3.5 ounces.
- Tofu is low in calories and fat, but high in certain minerals like calcium and iron.
- It has a very mild flavor and can absorb flavors from sauces, marinades and seasonings.
Tofu has been a staple food in China for over 2000 years. The process was first recorded during the Han dynasty. Its creation and use spread across East Asia, becoming particularly prevalent in Japan where it is known as doufu. Today, tofu is gaining popularity globally as more people seek plant-based and vegan protein sources.
How is Tofu Made?
Tofu production involves several steps:
- Selection and cleaning of soybeans: Soybeans with high protein and low fat content are chosen. They are soaked in water and thoroughly cleaned.
- Grinding soybeans into soy milk: The soaked beans are blended with water into a slurry and cooked. This produces raw soy milk.
- Filtering the soy milk: The soy slurry is filtered to separate out the soluble soy milk from the insoluble residue or okara. Multiple filtrations help improve taste and texture.
- Adding coagulants: Coagulants like calcium sulfate, calcium chloride, magnesium chloride etc. are stirred into the soy milk. This causes it to curdle and separate into curds and whey.
- Pressing the curds: The curds are poured into molds and pressed to form a solid block. More pressing results in firmer tofu textures.
- Cutting and packaging: The pressed tofu blocks are cut into slabs or cubes and packaged in water-filled tubs or vacuum packs.
The choice of coagulant and pressing techniques impacts the final tofu texture. Calcium sulfate yields silken tofu while calcium chloride produces firm tofu. More pressing pressure creates extra firm tofu. Manufacturers can produce soft, medium, firm, extra firm and silken tofu textures.
Types of Tofu
There are many varieties of tofu based on texture. Some common types include:
Silken tofu has a very soft, smooth and custard-like texture. It is made from soy milk without curdling and pressing. The end result is a creamy, gelatinous tofu that can be used in smoothies, desserts, dips and dressings. It has a high water content so does not hold its shape well when cooking.
Soft or Japanese-style tofu has a tender, delicate texture. It contains more moisture than firm or extra firm tofu. Soft tofu is made by coagulating soy milk and gently pressing the curds. It can be used in soups, sauces, smoothies, and lightly cooked dishes.
Firm or Chinese-style tofu is denser and holds its shape better than the softer varieties. It has been pressed to remove more whey and moisture, yet still retains some tenderness. Firm tofu can be stir fried, pan fried, deep fried or added to soups and stews. It has a versatile texture for marinating and absorbing flavors.
Extra Firm Tofu
Extra firm tofu contains the least moisture due to higher pressing. It has a dense, meaty texture that can stand up to cooking methods like grilling, broiling, roasting and baking. Extra firm tofu is ideal for skewers, burgers and in any recipe where you want a substantial, chewy texture.
Pressed or Dried Tofu
Pressed tofu has been pressed until most of the moisture is removed. Types like spiced tofu and Szechuan spiced tofu are pressed into blocks. Dried tofu is dehydrated even further until all moisture is extracted. It has a porous, crunchy texture and needs to be rehydrated before eating.
Here are the nutrition facts for a 3.5 ounce (100 gram) serving of firm tofu:
Key nutritional benefits of tofu:
- High in protein – Tofu is a plant-based source of complete protein containing all essential amino acids.
- Low in fat – It has much less fat than most meat and cheeses. Serving for serving, tofu has about 40% less fat than lean beef.
- Loaded with minerals – Tofu provides abundant amounts of iron, calcium, magnesium and other minerals.
- Source of B vitamins – It contains useful amounts of B vitamins including folate, thiamine and riboflavin.
- Low calorie – A 3.5 oz portion has only 76 calories, making it a smart choice when reducing calories.
Tofu is suitable for vegan, lacto-vegetarian and many other diets. It provides plant-based protein and nutrition without cholesterol.
Research has linked tofu consumption to a variety of potential health benefits:
Improved Heart Health
Several studies indicate that eating tofu can improve cholesterol levels and lower heart disease risk. In one study, people who ate half a serving of tofu daily instead of red meat saw a decrease in LDL “bad” cholesterol over an 8 week period. Tofu’s content of isoflavones, plant compounds with antioxidant activity, may be responsible for these cardioprotective effects.
Reduced Risk of Certain Cancers
The soy isoflavones in tofu may help lower the risk of breast, prostate and colon cancers. Population studies show lower cancer rates in regions with higher soyfood consumption. The isoflavones genistein and daidzein appear to inhibit cancer cell growth.
Relief of Menopausal Symptoms
Soy isoflavones can mimic estrogen in the body and help relieve hot flashes, insomnia and other menopausal symptoms. Consuming tofu daily provides a good dietary source of these protective isoflavones for middle-aged women.
The abundant calcium content in tofu promotes bone strength and health. Certain studies indicate that the calcium and isoflavones in soyfoods like tofu may prevent bone loss, especially in early menopause and postmenopause.
As a low fat, high protein food, tofu may aid weight loss. Replacing fatty meats with tofu reduces overall calorie intake. The protein keeps you feeling fuller for longer between meals, reducing appetite and overeating.
More research is still needed on tofu’s specific effects. But current evidence indicates tofu as part of a healthy diet can contribute to better health.
How to Select and Store Tofu
When buying tofu, choose fresh, packaged products with clean, clear liquid and no discoloration. Avoid packages with an off smell or cottage cheese-like lumps in the tofu. Check the expiration date and select the latest date for maximum freshness.
Once opened, leftover tofu blocks should be rinsed and covered with fresh water in an airtight container. Change the water daily and use within a week for best quality. Vacuum-packed tofu can be refrigerated unopened until the expiration date.
Freezing extra firm or firm tofu gives it a spongy, chewy texture when thawed. Remove tofu from package, wrap in a freezer-safe wrap or bag and freeze up to several months. Thaw in the refrigerator before using.
How to Cook With Tofu
Tofu’s subtle, neutral flavor allows it to take on the taste of accompanying seasonings and sauces. Here are some simple ways to cook with common types of tofu:
– Pan fry, deep fry or bake into crispy tofu cubes
– Skewer and grill or broil for BBQ tofu
– Add to stir fries and curries instead of meat
– Cubed and sautéed in garlic sauce or teriyaki
– Add to miso soup, stir fries, fried rice and noodle dishes
– Bake into casseroles and lasagnas
– Puree into dressings, dips, smoothies and desserts
– Add to Asian soups and gently simmered dishes
– Blend into vegan cheesecakes, mousses, puddings
– Use in salad dressings, dips, sauces and shakes
Marinating firms tofu in soy sauce, spices or other flavorful liquids infuses it with more taste. Breadcrumbing or frying also enhances flavor and texture. Explore using tofu as a base for vegetarian versions of egg salad, chicken salad and other recipes.
Common Tofu Dishes
Tofu is extremely versatile – here are some popular global tofu recipes to try at home:
A classic Chinese Sichuan dish of soft tofu cubes in a spicy, meaty sauce made from fermented beans, chili oil and aromatics. Often serves as a main course with rice.
General Tso’s Tofu
Crispy, deep-fried tofu is sautéed in a sweet and spicy General Tso’s sauce. A vegan take on the traditional chicken recipe popular in Chinese-American cuisine.
A vegetarian breakfast alternative to scrambled eggs, made by crumbling tofu seasoned with spices like cumin, turmeric and nutritional yeast. Often includes veggies like spinach and tomatoes.
Korean Dubu Jorim
Tofu braised in a thick Korean soy-based sauce accentuated with sesame oil, garlic, ginger and chili paste. Slow cooking allows the tofu to soak up maximum flavor.
Thai Tofu Pad Thai
Pad Thai is the classic Thai noodle stir fry. The tofu version subs cubes of pan-fried tofu for shrimp or chicken as the protein. Rice noodles, bean sprouts, peanuts and chopped aromatics complete the dish.
Vegan Tofu Tacos
Spiced crumbled or cubed tofu makes for flavorful vegan taco filling. Wrapped in tortillas or taco shells and topped with salsa, guacamole, lettuce and other taco fixings for a satisfying plant-based meal.
Japanese Tofu Steak
Thick slabs of tofu are marinated in soy, sake and mirin then pan seared or grilled until brown. Enjoy this meatless “steak” with rice and Asian vegetable sides.
Tofu and Veggie Stir Fry
Almost any combination of bite-size veggies and tofu strips, cubes or crumbles can be quickly stir fried on the stovetop with soy, sesame oil, garlic and fresh ginger.
With its mild taste and protein content, tofu is valued worldwide as a versatile meat substitute in vegan, vegetarian and omnivorous diets. This nutritious soyfood continues growing in popularity as more people discover its diversity in Asian and Western dishes. Experimenting with fresh tofu is an easy way to add more plant-based protein to your cooking.