Cooking Oils Under Heat: Which Ones Stay Stable and Which Ones Break Down?
Choosing the right cooking oil is not only about flavor. Under heat, oils change: some stay stable and protective, while others break down, oxidize and form unwanted compounds. This guide explains which oils handle heat best, which ones struggle, and how to match your oil to the way you cook. Why Heat Changes Oils in the First Place Cooking oils are mostly made of triglycerides — three fatty acids attached to a glycerol backbone. When you heat them, especially for long periods or to high temperatures, several things start to happen: Fatty acids oxidize (react with oxygen), forming peroxides and then secondary oxidation products. Double bonds break in polyunsaturated fats, which are more fragile than saturated or monounsaturated fats. Volatile compounds form , contributing to flavor but also to smoke and off-odors. Repeated heating accelerates polymerization and the formation of polar compounds and trans fats. Mod...