Protein coagulation
The process by which heat causes proteins to denature, unfold, and bond into a semi-solid network.
What it means in a kitchen
Egg whites begin to coagulate around 60°C; yolks set between 65–70°C. Holding temperature precisely within that window — rather than pushing past it — determines whether the result is silky, rubbery, or underdone. The same chemistry governs meat: myosin firms at approximately 50°C, actin at 65°C, which is why a steak held at 54°C has a fundamentally different texture than one cooked to 70°C. Understanding coagulation means reading the food's internal temperature, not the flame setting.
Common misunderstanding
Beginners treat coagulation as a binary state — raw or cooked — rather than a temperature gradient with a precise target zone. A poached egg white that weeps liquid and scrambled eggs that turn rubbery are both coagulation errors; neither is a seasoning problem.
Example
Holding poaching water at a steady 85°C keeps the white fully opaque while the yolk stays fluid, because yolk proteins coagulate 5–7°C above white proteins.