2. The brine used for tofu is a brine block formed after the mother liquor left in the salt pond is evaporated and cooled after being marinated in seawater or salt lake water, also known as brine and bittern. Its main components are sodium chloride, potassium chloride, magnesium chloride and calcium chloride, magnesium sulfate and magnesium bromide.
3. Brine is a traditional coagulant for making tofu in China for thousands of years. Brine blocks dissolved in water, called brine, are commonly used coagulants for making tofu in northern China, which can solidify protein solution into gel. Tofu made of brine as coagulant has strong hardness, elasticity and toughness, and is called old tofu, or north tofu and hard tofu.