Look at the color.

Brown green and yellowish kelp is normal. The kelp in brown green or yellowish brown is a normal color; The dark green kelp is made of fresh kelp that turns green after boiling, and then is processed through cooling, salinization, dehydration and other processes. It is generally used as cold dish; The emerald green kelp may be soaked by adding pigment, so consumers should pay special attention when choosing.

By the touch.

The kelp with brown green color is selected as the one with high viscosity, while the kelp with dark green color has no viscosity on the surface after processing. After chemical treatment, kelp has no toughness.

Smell the smell.

The taste of seafood is strong if the kelp has not been bleached. The taste of seafood is reduced if the kelp has been bleached.

Thin kelp salad, thick kelp soup. The thickness of kelp is related to its origin and growth period. The kelp produced in Fujian is thin and suitable for cold dishes. The kelp produced in Shandong and Dalian is thicker, and the stew and stew are better. In addition, kelp is picked at the early stage of growth. Its leaves are thin and smaller, so kelp at this stage is suitable for cold dishes. It is picked in the middle of growth. The leaves are thicker and larger than the early leaves. The kelp in this period has rich nutritional value and is suitable for stewing. The laminaria in the late stage has thicker leaves, but there are more attachments on the laminaria in the late stage. Although such laminaria can also be eaten, its nutritional value is much worse than that in the middle stage.

Dry kelp with hoarfrost. Kelp contains high iodine and a substance called mannitol. These two substances will attach to the surface of dry kelp in the form of white powder. Therefore, it is better to select dark brown dry kelp with white frost on the surface. If dry kelp is partially red or partially yellow, do not choose it. Such kelp may be polluted, and its quality and nutritional value will be poor. In addition, dried kelp also has a strong seafood flavor. If there are other odors, the quality of kelp is also discounted.