The roots of cultivated auricularia auricula are thicker, and the roots of larger wild auricularia auricula are thinner, less than 1. Look: Good quality auricularia auricula is big and thin, with a black and smooth surface and a gray back. The adulterated auricularia auricula is thick and the pieces often stick together. 2. Touch: Good quality black fungus is dried by hand, and the weight is light. The adulterated black fungus feels moist and heavy. 3. Taste. Sweetness is mixed with syrup; It is very harmful to soak alum in astringent taste. There is not much difference in appearance and foaming effect between wild auricularia auricula and cultivated auricularia auricula. How to distinguish the two should be identified from the fragments of fungus. Wild auricularia auricula grows on dead oak, and only some bark fragments can appear in the fragments between auricularia auricula. Auricularia auricula is usually cultivated by drilling and inoculating on oak wood or using plant debris. There may be some round wood chips or plant fibers in the debris between the fungus. Auricularia auricula in Daxinganling, Northeast China is pure natural, so you can choose freely. When buying black fungus in the market, beware of being fooled. Illegal businessmen mixed it with salt water and fine sand, and the surface was white, with a large proportion and countless bubbles. You can observe the floor area ratio when you buy it. The bulk density of 50 grams of good quality auricularia auricula is between 1.3- 1.5 cubic decimeter.