The basic difference between milk and milk powder Milk and milk powder are both dairy products produced by cows, but there are some basic differences between them. First of all, milk is produced by biological fermentation, while milk powder is manufactured mechanically. Secondly, the purity of milk is higher than that of milk powder, because milk powder usually also contains additives and condiments. In addition, milk powder is more convenient to store than milk, because milk powder can be stored at room temperature, while milk requires