Abstract: Deaerated oil having a level of less than about 0.10% by volume of dissolved oxygen is heated at a temperature between about 530.degree. F. (277.degree. C.) and about 650.degree. F. (343.degree. C.) and stripped with a stripping medium with a molar ratio of stripping medium to oil of between about 0.05 and about 9.7, at an absolute pressure of between about 0.5 mm Hg and about 50 mm Hg., for a time of between about 5 seconds and about 15 minutes. The combination of stripping parameters is selected so that the stripping factor "f" is greater than about 0.6, where f=KP.sub.v S/PO, where K is between about 1 and about 200, and where P.sub.v (the vapor pressure of the component to be stripped) is not more than about 0.1 mm Hg at 500.degree. F. (277.degree. C.) and not more than about 2.0 mm Hg at 600.degree. F. (343.degree. C.).