According to the person who sells duck blood in the vegetable market, it is the blood that people in the slaughterhouse directly collected in buckets when killing pigs, and then there is spilled blood, that is, the spilled blood is mixed with water and mixed with an edible glue and seasoning, and after it settles, the top layer of water (similar to serum) is skimmed off, and then the bottom layer is "duck blood"! Of course, the vegetable market should be real duck blood, and the fake one is usually sold directly to the restaurant with a small facade!