The primary ingredient in tofu is soybeans. Tofu, also known as bean curd, is made by coagulating soy milk and pressing the resulting curds into solid white blocks. This process typically involves the addition of a coagulant, such as magnesium chloride or calcium sulfate, which helps the soy milk curdle. Tofu is a versatile food that can be prepared in various ways—fried, grilled, or included in soups and salads. It is popular in vegetarian and vegan diets due to its high protein content and ability to absorb flavors from other ingredients, making it a staple in many cuisines.