According to the comparison of texture, there are probably the following criteria to evaluate the level of bird's nest:
Bird's nest cups are distinguished by "dense, thin and sparse". The denser one is classified as the top swallow cup, and the thinner one is inferior. Generally, cup-shaped complete fibers are closely classified as Grade I, while cup-shaped incomplete fibers are not closely classified as Grade II.
According to the cup type, the cup type is complete and symmetrical.
According to the comparison of bird's nest types and the classification of bird's nest quality, it is official swallow, hairy swallow and grass swallow in turn.
Official swallow: the first-class bird's nest with complete lamp shape and few impurities, usually called "official swallow" and "tribute swallow". This kind of bird's nest is the most nutritious, with few impurities and good taste. Tradition also has a name, that is, the first quality Bai Yan is called Yan Guan.
Mao Yan: A kind of bird's nest with more feathers, or the second and third stage bird's nest. The nutrients are not as good as those in Yan Guan, and there are many impurities, so it is difficult to handle.
Grass swallow: A kind of bird's nest built in grass, which is mixed with a lot of grass clippings and has the worst quality.
According to the color contrast of bird's nest, bird's nest can be divided into Bai Yan and blood swallow. Comparing the quality and price of bird's nest is actually controversial. A large number of data show that the first phase of bird's nest in Bai Yan has the highest content of unique components, and the difference between them is not very big. However, because the production of blood swallow is very rare, and it has a special texture and taste, sometimes the market price is slightly higher than that of Bai Yan.
Maintenance of bird's nest: generally, if it is very dry, it can be stored at room temperature. If the water content is slightly higher, it needs to be stored in the refrigerator. This kind of bird's nest will grow mildew at room temperature. After all, it belongs to protein. If the stewed bird's nest is cooked, it needs to be put in the refrigerator.