RBD palm stearin and RBD palm olein are obtained by the fractionation of RBD palm oil; whereas RBD palm kernel stearin and RBD palm kernel olein are obtained by the fractionation of RBD palm kernel oil. Through the process of crystallisation, RBD oil is cooled until crystals are formed.
The crystallised oil in the crystalliser is then filtered through a membrane to separate the liquid fraction i.e. olein from the solid fraction i.e. stearin. RBD palm olein is usually sold as cooking oil and may undergo further fractionation depending on the quality required.