The Food Lab: Better Home Cooking Through Science

which the oil actually catches on fire) can vary from
oil to oil but are generally in the 375° to 550°F range
—well below the actual boiling temperature of oil.
What you are seeing in a pot of “boiling oil” is not
the oil boiling. You’re seeing the water content of the
food you are frying in it boiling and bubbling its way
up through the oil, giving you the illusion that the oil
is bubbling. As soon as you take the food (and,
therefore, the water) out, the boiling will stop.† † †