Amount or Proportion of Egg

Proteins in an undiluted egg properly coagulate by about 160°F (70°C). Dilute the egg with milk, water, or other ingredients, and the coagulation temperature increases. For example, the coagulation temperature for most vanilla custard sauce formulas is between 180° and 185°F (82°–85°C). The dilution of egg proteins with milk, sugar, and cream makes it more difficult for the proteins to bump into one another and bond. This reduces the risk of overcoagulation. When bonding does eventually occur, expect a softer, more tender product as the additional liquid is trapped in the coagulated protein network.