I'm going to get this out of the way right from the start: to make Hollandaise sauce, you are absolutely going to have to make clarified butter. It helps stabilize your sauce, so that it doesn't curdle, and it really does make a difference.
Required tools for making clarified butter: A pot. A spoon. Seriously, you've got this. Mostly it's a matter of standing in your kitchen for half an hour while some butter melts in a pan.
For the Hollandaise itself, you'll also need a glass or stainless steel bowl, and a whisk, in addition to the aforementioned pot. Required skills: Pouring. Stirring.
All else being equal, you'd prefer a warmer kitchen over a cooler one, since warmer temperatures help the egg yolks to emulsify with the melted butter. That's one reason the Hollandaise at that brunch place you love so much is so amazing — their kitchen is probably roughly the same temperature as Hades. (The main reason, of course, is the cook there makes Hollandaise sauce every single day, and is probably borderline obsessive about it.)
For our purposes, if all you do is let your eggs come to room temperature before you start cooking, you'll be helping yourself out tremendously. Just take them out of the fridge a couple of hours beforehand. The butter, too, of course, but you don't keep your butter in the refrigerator, do you?
- 1 cup clarified butter (about 2½ sticks before clarifying)
- 4 egg yolks
- 2 tablespoon lemon juice (the juice from 1 small lemon)
- 1 tablespoon cold water
- Kosher salt, to taste
- Cayenne pepper (or a dash of Tabasco sauce), to taste
- Heat an inch or two of water in a saucepan over a medium heat. Also, your clarified butter should be warm, but not hot.
- Combine the egg yolks and the cold water in a glass or stainless steel mixing bowl (not aluminum) whisk for a minute or two, until the mixture is light and foamy. Whisk in a couple of drops of lemon juice, too.
- The water in the saucepan should have begun to simmer. Set the bowl directly atop the saucepan of simmering water. The water itself should not come in contact with the bottom of the bowl. Whisk the eggs for a minute or two, until they're slightly thickened.
- Remove the bowl from the heat and begin adding the melted butter slowly at first, a few drops at a time, while whisking constantly. If you add it too quickly, the emulsion will break.
- Continue beating in the melted butter. As the sauce thickens, you can gradually increase the rate at which you add it, but at first, slower is better.
- After you've added all the butter, whisk in the remaining lemon juice and season to taste with Kosher salt and cayenne pepper (or a dash of Tabasco sauce). The finished hollandaise sauce will have a smooth, firm consistency. If it's too thick, you can adjust the consistency by whisking in a few drops of warm water.
- It's best to serve hollandaise right away. You can hold it for about an hour or so, provided you keep it warm. After two hours, though, you should toss it — it'll eventually start to separate, and food safety also starts to become an issue.