Tofu koji is specially used to make mold grow on tofu and can be used to make fermented bean curd and hairy tofu. Fermented bean curd is a fungus of the Aspergillus family, purple Monascus. Fermented bean curd, also known as fermented bean curd, is a characteristic traditional folk delicacy that has been passed down in China for thousands of years. Because of its good taste and high nutrition, it is an enduring delicacy.