In Crème Anglaise, egg yolks are beaten vigorously with sugar, also unwinding the proteins. Hot milk or cream is whisked in gradually, and the liquid is heated slowly on top of the stove to make a smooth, custardy sauce. In this case, excessive heat (not too much beating) will cause the yolk proteins to rebel and make a fuss by curdling and turning into a sea of protein knots floating in milk.
- 4 large egg yolks
- 1 pinch salt
- 1/2 cup sugar
- 2 cups whole milk or half and half or a combination heated to almost the boiling point
- 2 tsp pure vanilla extract
Whisk the yolks and salt in a heavy medium saucepan until thick and lemon colored. For a thicker and richer sauce, add two extra egg yolks.
Gradually add the sugar, say 2 tablespoons at a time, and whisk well.
When all the sugar has been added continue whisking with fervor until the yolks are very thick.
Gradually—just a tablespoon or so at first—whisk in the hot milk. When the eggs are warm, you can add the milk faster. If you add the hot milk too quickly in the beginning you run the risk of cooking and curdling the yolks.
Scrape the pan with a heatproof rubber spatula and set over medium-low heat.
Cook, stirring constantly with the spatula, until the sauce reaches a temperature of between 175 and 180 degrees. When you swipe a finger along the length of the spatula blade, it will leave a clear path.
Pass the Crème Anglaise through a fine strainer. Cover and refrigerate and serve very cold. The sauce will thicken in the cold. The sauce will keep well for 5 to 7 days.