Step 1

Melt the butter. Use 8 tablespoons butter for a thick hollandaise for dipping or dolloping; use up to 16 tablespoons to make a thinner, pourable sauce. Cut the butter into a few large pieces and place in a microwave-safe measuring cup. Microwave in 30-second bursts until the butter is completely melted. Use the butter when it is no longer piping hot, but is still very warm; if it is no longer warm, re-warm the butter in the microwave. (Alternatively, melt the butter in a small saucepan over medium-low heat.)

Step 2

Blend the yolks, lemon juice, and salt. Place the egg yolks, lemon juice, and salt in a blender and pulse to combine.

Step 3

With the blender running, slowly stream in half the warm butter. With the blender running and the top open, slowly stream in the warm butter — start with a few drops, then a thin drizzle. Once you've added about half the butter, check the sauce (you can stop the blender if you need to). If it looks grainy or separated, see "Fixing a Broken Sauce," below.

Step 4

Continue adding butter in a steady stream. If the sauce is looking good, you can pour the butter a little more quickly in a steady stream. Continue pouring the butter and occasionally checking the sauce until the sauce is as thick or thin as you'd like, or you've added all the butter. When done, the hollandaise should be light yellow with a smooth, uniform consistency.

Step 5

Taste and adjust the sauce. Stop the blender and taste a small spoonful. It should taste rich, buttery, and slightly tangy. Stir in a little salt, cayenne, or lemon juice, if needed. If the sauce seems a little too thick to you, blend in some water a tablespoon at a time until the sauce is as thin as you like it.

Step 6

Serve the sauce. Hollandaise is best served as soon as it's ready, while still warm. If you need to, you can transfer the sauce to a double-boiler and keep it warm over low heat on a back burner, or set over a bowl of very hot water, for about an hour. The thicker and more mayonnaise-like the hollandaise, the more stable it tends to be; thinner sauces will break more easily — especially if they are held for too long before serving or if they get too cool. See "Fixing a Broken Sauce," below, for more information.