Reaching the smoke point is undesirable for any oil used in cooking because it changes the chemistry of the oil in an undesirable way. There are studies that claim that all extra virgin olive oils have a smoke point of 300 degrees but such studies ignore variable factors such as chemistry and freshness, which affect the smoke point. The truth is that the smoke point of an extra virgin olive oil will depend on its unique characteristics.
Supermarket olive oil labeled as “extra virgin olive oil”, which is not adulterated with refined oil, but is of a typical poor quality as a result of lax processing standards, age, UV light exposure, and poor handling tends to be highly oxidized and or rancid by the time the consumer purchases it. Highly oxidized or rancid olive oil lacks the protective chemistry that would otherwise allow for heating at higher temperatures before reaching the smoke point.
Fresh extra virgin olive oil of superior quality – boasting exceptional chemistry (i.e. high oleic acid content, very low FFA, and robust phenol count) – can be heated to greater temperatures before reaching the smoke point.
If you are looking to heat extra virgin olive oil up to 400+ degrees, pay close attention to the chemical make-up and choose one that is very fresh and chemically robust.