When making a stirred custard sauce, the hot liquid is slowly whisked into the egg yolks in order to not cook the eggs. What is this called?

• A. Tempering
• B. Fermenting
• C. Emulsifying
• D. Whisking

Answer: (A)

Tempering is the technique of gradually warming eggs by whisking hot liquid into them before returning the mixture to the pan. This slow introduction of heat prevents the yolks from cooking too quickly and curdling, producing a smooth custard. In a stirred custard sauce, you whisk hot liquid into the yolks slowly to equalize the temperature and avoid scrambling. Once tempered, you can combine the yolk mixture back with the rest of the hot liquid and cook gently until it thickens. Fermenting involves microbes, so it’s not about heat control; emulsifying is about blending two immiscible liquids, and whisking alone is just mixing without addressing the temperature issue.