Gypsum tofu has a fine texture, good water retention, high product yield, easy coagulation, but the soy flavor is not enough, often with gypsum residue, accompanied by gypsum flavor.
Based on the different coagulants used, the domestic production and sale of tofu can be divided into salt brine tofu (also known as brine tofu), gypsum tofu, acid coagulation tofu. Salt brine tofu has the best flavor, but poor water retention, low yield, coagulation operation is difficult. Gypsum tofu has a fine texture, good water retention, high product yield, easy coagulation, but the soy flavor is not enough, there is often gypsum residue, accompanied by gypsum flavor. Acid-coagulated tofu includes sour milk tofu and gluconolactone tofu (referred to as lactone tofu or GDL tofu). Acid-coagulated tofu has a bland flavor, fine texture, and good water retention, but is significantly less strong. Because of the poor water retention of salt brine tofu, it is generally made into the firmer texture of northern tofu, while acid-coagulated tofu has good water retention, so it all belongs to the softer texture of southern tofu. Only gypsum tofu, its water retention between the two, both can be made of northern tofu, but also can be made of southern tofu. In the north of China, salt brine tofu enjoys a very high reputation, but the rate of acquisition is low, some producers and sellers of gypsum tofu often pretend to be salt brine tofu. Sour paste tofu is only in individual areas of production, production is small. Lactone tofu is a new type of acid-coagulated tofu developed in Japan in the 1960s, and its coagulation molding mechanism is suitable for the production of boxed filled tofu. Boxed lactone tofu has a longer shelf life, easy to transport, as a new variety of tofu, the current market sales increasing day by day, but because of the lack of strength, is not suitable for cooking and frying of the strong turning, and the lack of soybean flavor, but also slightly sour, so it is not possible to replace the traditional tofu made with salt brine, gypsum.
For fresh tofu quality indicators, in addition to moisture content, there should be two, one is the texture of tofu parameters, the second is the water retention properties of tofu. The textural parameters of tofu, i.e. strength, elasticity, cohesion, chewiness directly reflect the taste of tofu, while the water retention performance of tofu directly affects the yield, circulation and sales of tofu.
Types and names of commercially available fresh tofu in China
Tofu name Moisture content of common coagulants Chinese alias Foreign similar products
Tofu Brain 95% or so Gypsum, GDL ① Soybean curd
Southern tofu 85% to 90% Gypsum, GDL, sour water ② Tender Tofu, Soft Tofu, Water Tofu Kinogoshi (silken tofu), silken tofu, soft tofu
Northern tofu 80%～85% Brine, salt brine, gypsum Old tofu, hard tofu, slab tofu, regular tofu Momen tofu (kapok tofu), regular tofu
Dry tofu 60%～70% Brine, salt brine Soybean sheets (thickness of 10～20mm）
百叶（厚度为2mm左右）
千张（厚度为0.5mm左右） Dried tofu
Filled tofu ③ 90% or so GDL Boxed tofu, Lactone tofu Filled tofu, packaged tofu
①GDL: Glucono-delta-lactone.
②Sour syrup water: yellow syrup water not fermentation liquid.
③Filled tofu: not traditional tofu.
The main types of foreign tofu products are slightly different from China. China's production of large quantities of northern and southern tofu, while Japan's production of large quantities of kapok tofu (momen tofu) and silken tofu (kinogoshi,silken tofu). Japanese momen tofu is equivalent to our northern tofu in terms of processing methods and product characteristics. Japanese silken tofu is different from China's southern tofu, mainly in two aspects: First, silken tofu requires a higher concentration of soymilk; Second, the southern tofu solidification needs to be transferred to the type of box, applying a certain amount of pressure to drain a certain amount of water, while the silken tofu solidification only need to be cut into pieces after cooling. In terms of product characteristics, the moisture content of silken tofu is basically the same as that of southern tofu, and may sometimes be higher. In Japan, soft tofu is produced in the same way as Chinese southern tofu, except that it is produced in smaller quantities. China's filled tofu is the same as Japan's, and its soy milk consistency and product texture are basically similar to that of silken tofu, both of which do not require pressurized draining, but filled tofu is added to the coagulant at room temperature, while silken tofu is added to the coagulant at 70-80OC.
The tofu used for further processing is generally less moisture content of the northern tofu and semi-dry tofu. Tofu processing products are very rich, according to the production method can be divided into frozen products (i.e., frozen tofu), fermented products (i.e., fermented bean curd), halogenated products, fried products, smoked products, alkali dipped products and fried halogenated products, etc., and will not be discussed in detail here.
The above is only a preliminary classification of China's traditional tofu products. It should be noted that the same product between different regions, between different producers in the same region, whether in the production process, or in the product quality requirements, there are certain differences. Especially in the product name and production operation terminology, between different regions vary widely, quite confusing.
Brine and gypsum are necessary for pointing tofu. But whichever one is used, the practice is different from place to place. First take the dry tofu it, the northern practice to do out of the thinner, strong. In the south, it's thicker. Tofu made in the north is very tender, moisture, put in the hand feels like it will break. In the south, it is less watery and more firm. The custom of each place is different, so it's natural to make it differently. If you have the chance, you can experience the real authentic tofu of the north and south!
Flavor: Marinated tofu is tough and hard, with a soybean flavor, and gypsum tofu is tender and smooth.
Color: Gypsum tofu is whiter than brine tofu.