Appearance: the good freeze-dried powder looks fluffy, while the inferior one forms a solid package and feels hard and rough; True factor freeze-dried powder should be colorless, claiming to be special effect freeze-dried powder. If it is colored, it must have added some effective ingredients, not real factors. B. Dissolution: Speed: Good quality freeze-dried powder should be very soluble in water, that is to say, the enzyme and freeze-dried powder will dissolve quickly after mixing, while the bad one will dissolve slowly or not at all, but there are many suspended substances that feel like impurities.