Deep frying is simultaneously surface dehydration and interior steam cooking — two processes happening at different rates in the same oil. The moment food enters hot oil, surface moisture flashes to steam and escapes through the forming crust. The outward flow of steam prevents oil penetration during the active frying phase. When frying ends and the food is removed, the steam pathway closes and oil wicks into the crust through capillary action. Understanding this mechanism explains why food absorbs oil after removal from the fryer (not during), why colder oil produces greasy food (oil penetrates before the crust forms), and why surface moisture before frying produces greasy, soggy results.
Modernist Cuisine