Old Beijing Stinky Tofu

Old Beijing Stinky Tofu

　　　   Stinky tofu is a fermented tofu product that is popular across China and in many other parts of the world, but its preparation methods and ways of eating vary greatly from place to place. There are two main types: dried stinky tofu and stinky tofu paste, both of which are very popular snacks. Stinky tofu paste was once served as a side dish in the imperial court and was favored by Empress Dowager Cixi, who even gave it the royal name "Imperial Green Cube." In Shanghai and Taiwan, stinky tofu is a highly representative snack.

　　   How Old Beijing Stinky Tofu Is Made:

　　   1. Making the tofu: Soak soybeans in water until softened, then rinse them clean with fresh water. Replace the water with 20–25 kg of clean water, grind the beans into a thin paste using a stone mill, then mix in an equal amount of warm water. Pour the mixture into a cloth bag and squeeze out the soy milk. Mix the remaining soybean dregs with boiling water, stir well, and squeeze again. Repeat this process until the dregs no longer stick to your hands and all the soy milk has been extracted. Skim off any foam, then boil the soy milk in a pot over high heat, pour it into a vat, and add gypsum solution while stirring continuously with a stick. Stir about 15–20 times, then test by dropping a little water into the mixture—if it blends with the soy milk, more gypsum is needed. Stir in additional gypsum and continue mixing. If the water doesn’t blend, the mixture will turn into tofu curd after about 20 minutes. Scoop the curd into a wooden mold, cover it with a wooden board, and press it with heavy stones to remove excess water and form tofu. For making stinky tofu, the tofu must be specially made—firmer than regular tofu but softer than tofu dried.

　　   2. Fermentation: Arrange the freshly made tofu on wooden shelves, which can hold several layers with proper ventilation in between. Sprinkle salt on the tofu and apply mold (the mold spores are dissolved in water and applied to the tofu with a finger). Place the tofu in a ventilated room away from direct sunlight for two to three days. In summer, the room temperature may reach around 32°C, and white mold (about an inch long) will grow on the tofu.

　　   3. Post-fermentation treatment: Place copperas (iron sulfate) in a bucket, pour in boiling water, and stir with a stick to dissolve. Soak the tofu in the solution for about two hours, then take it out and let it cool. Next, soak the tofu in brine—about 3–5 hours in spring and autumn, around 2 hours in summer, and 6–10 hours in winter. After soaking, take the tofu out, rinse it briefly with cold water, and drain off the moisture. (Brine preparation: Using 2.5 kg of fermented soybean paste as a standard, boil it in 15 kg of water, filter the liquid, then add 1,500 g of alkaline and let it ferment for about half a month, stirring once a day. The resulting liquid is the brine.)

　　   4. Further processing is done according to regional taste preferences and characteristics.