Salt in cooking operates through multiple distinct mechanisms — osmosis, protein denaturation, water activity reduction, and flavour enhancement — and understanding which mechanism is relevant to a specific application determines how salt should be used, how much, and when. Salting a steak 40 minutes before cooking is a completely different physical act from salting it 2 minutes before, or salting it 24 hours before (dry brine). Each produces a different result through a different physical mechanism.
Modernist Cuisine