Soaked soybeans in water, soaked and softened, ground into soybean milk, and then filtered out the dregs, boiled. At this time, the protein particles in the soybeans are water clusters constantly moving, can not be gathered together, the formation of a "colloid" solution. To make the colloidal solution into tofu, you must point brine. Spot brine with salt brine or gypsum, salt brine contains mainly magnesium chloride, gypsum is calcium sulfate, they can make the dispersed protein particles quickly gathered together, into a white tofu brain. Then squeeze out the water, tofu brain becomes tofu. Tofu, tofu brain is cohesive soy protein.

Brine point tofu has the meaning of one thing to another. The scientific name of brine is salt brine, after boiling salt with brine salt water, the black liquid left is salt brine, a mixture of magnesium chloride, magnesium sulfate and sodium chloride, which is the reason it can kill people. Eating tofu is fine because the salt brine content within the tofu is very low.