1, Observe the appearance: The real snow swallow is made of the gum spit by the snow swallow, which has the characteristics of transparency, smoothness and neatness. The fake snow swallow is often synthetic, with rough appearance and uneven color.

2. Smell: The real snow swallow has no special smell, while the fake snow swallow may have the smell of artificially added spices or chemicals.

3, soaking test: put the snow swallow in warm water to soak, the real snow swallow will gradually spread out, forming a gel.

4. Color and size: The color of real snow swallow presents a unique light yellow, while the color of fake snow swallow may present unnatural white or yellow. A snow swallow is not very big, but usually a small one. A poor snow swallow will be bigger.

Artificial snow swallow usually refers to the food that imitates the appearance and taste of natural snow swallow, which may be made by artificial synthesis or extracted from plants by a specific process. Xueyan is a natural gelatinous secretion of Malus, which is similar to peach gum in nature and mainly produced in tropical and subtropical regions. The formation of snow swallow is made by cutting the trunk of apple tree artificially, punching holes to collect pith secretions, and then air drying. Snow swallow is as crystal clear as crystal when it is just secreted. After being oxidized by air, its color gradually turns yellow, forming red, black and brown snow swallow. Snow swallow has a sour taste when it is secreted, but the sour taste will disappear after soaking, and there will be no sour taste when eating.