This document describes the process of determining the saponification number of fats and oils. Saponification is the hydrolysis of triacylglycerols into glycerol and potassium salts of fatty acids when refluxed with an alkali such as potassium hydroxide. The saponification number is the number of milligrams of potassium hydroxide required to neutralize the fatty acids from the complete hydrolysis of 1 gram of fat. A higher saponification number indicates shorter fatty acid chains on average, while a lower number indicates longer chains. The process involves refluxing a fat sample with alcoholic potassium hydroxide, then titrating the excess alkali to determine the number of milligrams needed to s