What is the Main Ingredient to Make Tofu?

December 21, 2025 •

2 min read

Originating in China over 2000 years ago, tofu is a staple in many cuisines and is praised for its versatility and nutritional value. But before it becomes the familiar white block, the process begins with a single key component. Discover what is the main ingredient to make tofu and how it's transformed.

Quick Summary

Tofu's core is the soybean, a legume processed to create soy milk. This milk is curdled with a coagulant and pressed into solid blocks, forming the final product. The firmness varies based on water content.

Key Points

Soybeans are the primary ingredient: All tofu starts with soaked and ground soybeans, which form the base for soy milk.
Soy milk is a key intermediate: The soybeans are processed to create soy milk, which is then curdled to begin the tofu formation.
Coagulants are essential: Agents like nigari or gypsum are used to coagulate the soy milk, separating the curds from the whey.
Pressing determines firmness: The amount of water pressed out of the curds dictates whether the final tofu is silken, firm, or extra-firm.
Minimal ingredients, maximum versatility: Traditional tofu is made with only soybeans, water, and a coagulant, resulting in a protein-rich food that can be used in countless dishes.
Historical roots in China: The art of making tofu originated in China over two millennia ago.

The Fundamental First Step: Soybeans

Tofu is also known as 'bean curd,' and its main ingredient is the humble soybean. Much like how dairy cheese is made from milk, tofu is made from soy milk. The process begins by soaking and grinding dried soybeans into a thick slurry. This mixture is then cooked and strained, separating the solid pulp, known as okara, from the resulting liquid: fresh, warm soy milk. It is this soy milk, rich in protein, that provides the essential building blocks for tofu.

The Curdling Process with a Coagulant

Once the soy milk is ready, a coagulant is added to cause the proteins to solidify and form curds. This is the critical step that separates the smooth, liquid soy milk into solid curds and a watery liquid called whey. The type of coagulant used can influence the final texture and taste of the tofu. Common coagulants, used in both commercial and homemade tofu production, include salt-based, acid-based, and even some natural derivatives.

Common Tofu Coagulants

Nigari: A traditional Japanese coagulant consisting primarily of magnesium chloride, often sourced from seawater after salt extraction.
Gypsum: Calcium sulfate, a salt coagulant that helps create a smoother, more tender tofu.
Glucono Delta-Lactone (GDL): An acid-based coagulant used primarily for making very soft or silken tofu and tofu puddings.
Acidic Agents: More accessible options like rice vinegar or lemon juice can also be used, though they may yield a slightly different texture and flavor.

Pressing and Shaping the Curds

After the curds have formed, they are transferred into a mold lined with a cheesecloth or muslin cloth. Pressure is then applied to the curds to drain off the excess whey. The amount of pressure and the duration of the pressing process determine the final firmness and texture of the tofu block. Less pressing results in softer, more delicate tofu, while more pressure yields a denser, firmer block.

The Resulting Textures of Tofu

This pressing stage is crucial for creating the variety of tofu textures available in the market. From silken to extra-firm, the water content is the main differentiator.


Tofu Type	Firmness	Water Content	Best For
Silken	Very Soft	Highest	Smoothies, creamy dips, sauces, desserts
Soft	Soft	High	Soups (like miso), dressings, baked goods
Firm	Firm	Medium	Stir-fries, pan-frying, baking, absorbing marinades
Extra-Firm	Very Firm	Lowest	Grilling, deep-frying, hearty stir-fries

Conclusion: The Simple Power of Soy

In summary, the main ingredient to make tofu is the soybean. Through a process of creating soy milk, adding a coagulant to form curds, and then pressing those curds, soybeans are transformed into the versatile, protein-rich food that has been enjoyed for centuries. The simple combination of soybeans, water, and a coagulant highlights how minimally processed foods can offer incredible nutritional value and culinary flexibility. Tofu's ability to absorb flavors and take on different textures makes it an invaluable ingredient for many recipes. For a more in-depth look at tofu's nutritional benefits, you can consult this Healthline article on the topic.

Frequently Asked Questions

Yes, but it is important to use high-quality, unfortified soy milk with only soybeans and water as ingredients, as additives can prevent coagulation.

The firmness depends on how much water is pressed out of the soy curds. More pressing results in firmer tofu.

Yes, tofu contains all nine essential amino acids, making it a complete protein source, which is beneficial for plant-based diets.

The liquid that separates from the curds is called whey.

The pulp left over after straining the soy milk is known as okara, which can be used in other recipes.

Nearly all tofu is vegan, but some rare varieties found in Asian stores, sometimes called "egg tofu," may contain eggs for texture.

Yes, with soaked soybeans, water, a coagulant, and basic kitchen tools, it is a straightforward process to make homemade tofu.