SummaryWith mild agitation, soybean oil is not appreciably contaminated by contact with clean steel surfaces unless the fatty acid content is above 0.1% and the temperature above 150°C.It has been shown that an oxidized oil film is an effective coating for metals used in the construction of pilot‐plant deodorizers. Such a film, to be most effective, should be washed free of unoxidized, noncoherent oil with a suitable solvent. If the metal is properly coated an oxidation‐stable and flavor‐stable oil can be obtained from the deodorizer, providing the oil has been properly refined and bleached. The oil film is nearly the equivalent of a glass surface in its effect on oil stability, is easily formed on a metallic surface, and can be readily removed when the metal is cleaned with caustic.A silicone varnish film baked on the metal surface is somewhat less effective than an oil film. Other methods of treating steel or stainless steel, which include coating the metal with a polymeric ether‐linked wax, grit‐polishing, and electropolishing, are fairly effective in reducing corrosion of the metal during deodorization.