From the appearance, crisp yam is smooth, which is suitable for frying; If you are stewing soup or making dessert dishes, it is recommended to choose noodle yam, which will taste sweet and full. Noodles yam is characterized by more pockmarks, more whiskers and smoothness.
Look at the appearance. Slightly flat, with a little bend on the head, the color is brown; Or the stem is straight and the texture is solid; Or in the shape of a small hand, it is a good yam. If there are bumps, the taste may be slightly harder.
Then hold it in your hand. Hold yam for a period of time, the length of time can depend on the weather at that time, the warmth can be shorter, on the contrary, the holding time can be longer. After holding and releasing, the fresh yam skin has a warm feeling; The stale yam will "sweat" and the epidermis will ooze tiny water drops, which is the frozen yam. Once the yam is frozen, the contents of polysaccharide and free amino acids in the mucus will be damaged, the nutritional value will be reduced and the taste will be poor.