1. Variety: Different varieties have different grades. For example, in general, red mouth is better than North Sea fish glue, and North Sea fish glue is better than cod glue.
2. Size: The larger and thicker the size of similar colloids, the better the quality. The so-called "one glue and ten pounds of fish". It can be seen that a few kilograms of glue, the fish body has dozens of kilograms.
3. Glue age: The darker the color of glue, the older it is. The advantage of aged gum is that the concentration of gum is reduced, which makes nutrients more easily absorbed by human body and has a nourishing effect. There is no need to eat our old glue, but the objective fact is that the old glue is really better than the new one.
4. Dryness and humidity: The drier the glue, the better. Generally speaking, old glue will dry out because it has been left in Chen Fang for a long time.
5. Choice of male and female: Flower glue is divided into male and female. Flower gum is saddle-shaped, with a thick belly in the middle and thin sides with V-stripes. The texture is firm, thick, dry, light, golden yellow and translucent. It is firm and elastic after cooking. As for the "wide belly", it is slightly round and flat, shaped like a wavy plate, horizontal or wavy, thin, easy to dissolve after cooking, soft in taste and cheaper in price. Rubber men are better than rubber women.
There are other factors, such as origin, smell, goods and so on.