15 Water

Don’t forget that 100 minus the total solids content = water. This water comes from liquid ingredients such as milk and cream, or liquid sweeteners, or it cn be added water. You can easily make a mix from cream, skim powder, water, etc., or even butter, skim powder, water, etc. The water content has to be potable of high quality, but the hardness is of less concern due to the high mineral content coming from the milk solids-not-fat.