Different cultures often prefer different textures of tofu. The resulting protein-lipid coagulated mixture is placed into a molding box to form the soy curd, or tofu. While there are only three basic steps in tofu making, it is complex and difficult to make a reproducible high-quality product. The quality of the beans, the amount of stirring the coagulants, and the pressing of the curd can have a high impact on the quality of the final product.
Calcium sulphate creates a bridge by which the soy proteins in the milk can aggregate.
The resulting tofu product is affect by such things as pH, concentration of the coagulate, and the rate the product is stirred. The isoelectric point for soyproteins is pH4.2. At this point,t he elimination of electrical repulsion charges allow the proteins to aggregate. Lemon juice and vinegar can be used as alternatives to calcium sulfate as they reduce the pH of the system and allow this to happen. Drain and rinse.