Burnt oil can polymerize into a hard film that does not come off with ordinary dishwashing. On stainless steel, soften the layer with moderate heat and compatible cleaner before reaching for abrasives that can scratch the finish.
Remove loose grease before treating the burnt film
Wash with hot water and dish detergent to remove oil that is still loose. This lets the next step work on the hardened film instead of spreading grease around the pan.
Soften the residue with hot water and dwell time
Add enough water to cover the residue and warm it in a controlled way if the cookware instructions allow; then let it sit and lift softened deposits with a nonmetal tool. Do not heat a dry pan containing cleaning chemicals.
Use a stainless-safe cleanser if film remains
A stainless-specific cleanser or approved mild abrasive can help with persistent film. Test first and rub with the finish; aggressive steel wool can scratch the pan or leave particles that later rust.
Rinse thoroughly and avoid overheating oil next time
Remove all cleanser residue before cooking again. Use a fat suited to the cooking temperature and reduce heat if oil begins smoking continuously because overheating promotes the hardened film.
Sources
- American Cleaning Institute — Cleaning Tips — Household cleaning methods, product use, dosing, and material compatibility.