Abstract: Methods for the removal of volatilizable components from a natural oil-based product having a high viscosity are provided. The natural oil-based product can be a high viscosity oligomeric polyol prepared from epoxidized vegetable oils. The method involves heating a natural oil-based product to relatively low temperatures (about 225° C. or below) and then exposing the natural oil-based product to an environment comprising a reduced pressure and a sparging vapor. In particular, deodorization methods are provided. In deodorization processes, odor components such as hexanal, nonanal, and decanal are substantially removed from the natural oil-based product. The lower temperature process provides effective removal of the volatilizable components, while maintaining desirable product properties, such as the clarity of the product, and chemical and physical properties similar to that of the starting material.