A. ‘Milk solids’ refers to the dried powder left after all the water is removed from liquid milk. It is similar to the milk powder you buy at the supermarket and can be full-fat or non-fat (skim).
Non-fat milk solids are often used to give a richer ‘mouth feel’ to low-fat yoghurts, milks and ice creams without adding any fat.
You'll often see this on the ingredient list as MILK SOLIDS NON-FAT on many light foods.
See MILK SOLIDS in the label snapshot which comes from a dried soup base of vegetables and barley that you pop into a slow cooker along with your own fresh vegetables. The milk powder is full-fat and gives a smooth creamy texture to the finished soup - in the same way that you add a dollop of cream or swirl in some milk at the end of cooking to round off a home-made soup.