The main ingredient used in making tofu is soybeans. Tofu is made by coagulating soy milk, which is created by soaking and grinding soybeans into a liquid. The resulting soy milk is then mixed with a coagulant, typically magnesium chloride or calcium sulfate, which helps the soy milk solidify. The mixture is pressed to remove excess liquid, resulting in the soft, versatile block of tofu. Tofu is a staple in vegetarian and vegan diets due to its high protein content and ability to absorb flavors from other ingredients, making it suitable for a variety of dishes, from stir-fries to salads.