Soap Stock

Soap stock is a byproduct of soap, resin acids and wax materials that are separated as a result of washing and neutralization of free fatty acids with caustic and in refining of vegetable raw oil. It contains water and low amount of oil. Used a raw material for soap, the soap stock is obtained during elimination of free fatty acids (alkaline refining) by caustic soda neutralization of raw oils.

During this process, soap is produced by adding sodium hydroxide solution (caustic) into raw vegetable oil in an amount and concentration determined based on free fatty acids content, according to its reaction, and then free fatty acids are separated from the oil in soap form.