Tofu is primarily made from what ingredient?

Tofu is primarily made from soybean milk curds, which is the process of coagulating soy milk to form solid curds. This is done by adding a coagulant, usually magnesium chloride or calcium sulfate, which helps the proteins and fats in the soy milk to solidify. The result is pressed into blocks that can vary in firmness, from silken to extra firm, depending on the amount of water that is removed. This essential ingredient makes tofu a rich source of protein and a staple in many vegetarian and vegan diets.

The other options do not form the primary ingredient in tofu. Wheat flour is used in various other products, such as noodles and bread. Corn starch and rice flour are also used in specific culinary applications but not in the production of tofu.