Coagulation

Appears in
Professional Cooking
Professional Cooking

By Wayne Gisslen

Published 2014

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Eggs are largely protein, so the principle of coagulation is important to consider.

Eggs coagulate at the following temperatures:
Whole eggs, beaten about 156°F (69°C)
Whites 140°–149°F (60°–65°C)
Yolks 144°–158°F (62°–70°C)
Custard (whole eggs plus liquid) 175°–185°F (79°–85°C)
Note that whites coagulate or cook before yolks do. This is why it is possible to cook eggs with firm whites but soft yolks.

Note also that when eggs are mixed with a liquid, they become firm at a higher temperature. However, 185°F (85°C) is still much lower than the temperature of a sauté pan or skillet over high heat. As the temperature of coagulation is reached, the eggs change from semiliquid to solid, and they become opaque. If their temperature continues to rise, they become even firmer. An overcooked egg is tough and rubbery. Low temperatures produce the best-cooked eggs.