2 egg yolks
1-1/2 tablespoons lemon juice, divided
1/4 teaspoon salt
1/4 teaspoon white pepper
4 ounces unsalted butter, cut into 8 1–tablespoon pieces
1 tablespoon water
For two servings:
1 egg yolk
2 teaspoons lemon juice, divided
1/8 teaspoon salt
1/8 teaspoon white pepper
2 ounces unsalted butter, cut into 8 pieces
1-1/2 teaspoons water
Makes about one cup.
Choose a small saucepan and a metal or heat–proof glass bowl that fits securely in the top of the pan. Put 1/2– to 1 inch of water into the saucepan (just enough that the water level doesn’t quite touch the bottom of the bowl when it’s set in the pan.) Set the pan over high heat. Once it boils, turn the heat down to keep the water at a bare simmer.
In the bowl, whisk the egg yolk(s), one tablespoon of lemon juice (1-1/2 teaspoons if making 2 servings), salt and pepper until the mixture is uniformly yellow and slightly thickened.
Set the bowl in the pan and whisk slowly but constantly until the mixture starts to thicken. Be sure to whisk throughout all parts of the bowl. (If steam starts to leak from underneath the bowl, turn the heat down a little.)
Add one piece of the butter. Continue whisking until the butter is incorporated, then add another piece of butter. Repeat until all the butter is incorporated. The sauce should be thick, smooth and glossy. Whisk in the water. Adjust seasoning, adding more lemon juice if desired.
Remove the pan from the heat. It will keep over the hot water for a half–hour or more, provided you whisk it occasionally. Alternatively, pour the sauce into a thermos or air pot until ready to serve.
For further refinement, strain the sauce to remove little bits of coagulated protein: simply pour it though a mesh strainer into the serving vessel.