Mao doufu (毛豆腐, literally hairy tofu) is a fresh tofu inoculated (accidentally or intentionally) with a white mold (Mucor genus, closely related to the mold used in some doufu ru fermentations) and allowed to grow a dense coating of white mycelium for 3-5 days at room temperature. The resulting tofu, covered in a thick white fur of mold, is then grilled or pan-fried until the mold exterior turns golden-brown and crispy while the interior becomes impossibly silky and slightly runny — the mold's proteolytic enzymes have broken down the tofu proteins during the fermentation, producing a texture midway between fresh tofu and custard. It is sold at street food stalls in the Huizhou region and at markets in Zhejiang.
The inoculation: Cut fresh firm tofu into blocks (approximately 5x5x4cm). The traditional method is to leave the tofu in a warm, slightly humid environment where natural mold spores from the environment inoculate the surface. For a controlled inoculation, purchase a piece of mao doufu with active mold growth and place it next to the fresh tofu blocks in a container — the mold will spread. Cover loosely with a cloth or paper. Incubate at 18-22C for 3-5 days. Grilling or pan-frying: The mold-covered tofu blocks are placed on a hot grill or in a lightly oiled skillet over medium heat. The mold fur will initially mat down, then begin to brown and crisp as heat drives off the surface moisture. Cook 3-4 minutes per side. The exterior should be golden-brown and slightly crackled. The interior should be warm, soft, and almost runny. Serving: With salt and chilli powder (Anhui style) or with a Sichuan-style chilli oil dressing.
Fuchsia Dunlop, Invitation to a Banquet (2023)