The process of refining reduces the free fatty acid, phospholipids, carbohydrates, or proteins. The most widely practiced form of refining method is an alkali treatment. By treatment of the fats and oils with an alkali solution, the free fatty acid converts into water soluble soaps. Phospholipids carbohydrates and proteins also can be changed to water soluble substances with hydration.After the alkali treatment, the fats and oils are washed with water to remove residual water soluble soaps.