from Volume 1 of “Mastering the Art of French Cooking” by Julia Child page 81
Makes ¾ cup
This very quick method for making hollandaise cannot fail when you add your butter in a small stream of droplets. If the sauce refuses to thicken, pour it out, then pour it back into the whizzing machine in a thin stream of droplets. As the butter cools, it begins to cream and forms itself into a thick sauce. If you are used to handmade hollandaise, you may find the blended variety lacks something in quality; this is perhaps due to complete homogenization. But as the technique is well within the capabilities of an eight-year-old child, it has much to recommend it.
3 egg yolks
¼ teaspoon salt
Pinch of pepper
1-2 tablespoons lemon juice
4 ounces (1 stick) butter
1. Place egg yolks, seasonings and 1 tablespoon lemon juice in the blender jar. You can beat in more when the sauce is done and will know what proportions you like for the next time.
2. Cut the butter into pieces and heat it to foaming hot in a small saucepan.
3. Cover the jar and blend the egg yolk mixture at top speed for 2 seconds. Uncover, and still blending at top speed, immediately start pouring on the hot butter in a thin stream of droplets. (You may need to protect yourself with a towel during this operation.) By the time two thirds of the butter has gone in, the sauce will be a thick cream. Omit the milky residue at the bottom of the pan. Taste the sauce and blend in more seasonings if necessary.
DO AHEAD: If not used immediately, set the jar in tepid, but not warm water.
For more sauce: The amount of butter you can use in a blender is only half the amount the egg yolks could absorb if you were making the sauce by hand, when 3 egg yolks can take 8 to 9 ounces of butter rather than the 4 ounces specified in the preceding recipe. However, if you added more butter to the blender than the 4 ounces specified, the sauce would become so thick that it would clog the machine. To double the amount of sauce, then, pour it out of the blender jar into a saucepan or bowl and beat into it an additional ½ cup melted butter added, in a stream of droplets.