Northern tofu is hard tofu, while southern tofu is soft.

Northern tofu is a kind of tofu that uses salt brine as a coagulant. It has great hardness and toughness, and the water content is about 80%-85%. It is rich in calcium, magnesium and protein. Each 100g of northern tofu contains 138 mg of calcium, 63 g of magnesium and 12.3 g of protein. Nan tofu is tofu that uses gypsum as the coagulant. It has a tender texture and a relatively high water content, usually around 85%-90%. Each 100 grams of southern tofu contains 116 grams of calcium, 36 grams of magnesium and 6.2 grams of protein.