Beurre blanc is one of the great culinary ironies -- a sauce as versatile and endlessly chic as the little black dress but nearly as simple to make as cutting up a stick of butter. (I don't actually have a little black dress, but I do have butter, so this is as chic as I get.) Which leads us to its next irony: It was popularized in the '60s and '70s by French chefs looking to lighten their cuisine, pooling it onto plates instead of their traditional, roux-heavy sauces, which means that it's a lightener that's 85 percent butter.
Look at its name. It means "white butter." That means it's awesome. But how is enough grease to run an outboard motor going to lighten up your food?
The key lies in two magical cooking concepts: acid balance and emulsification. You make this sauce with enough tart ingredients to counteract the richness of the fat, so that it plays a trick on your tongue, where you can taste both but neither dominates.
Emulsification also affects the way your palate perceives fatty things. Think of mayonnaise. If you tasted its component parts before they were blended together, you would be just pouring oil on your tongue, and you would wonder what you'd done to deserve this kind of punishment. But once emulsified ... incredibly delicious! The emulsification causes the oil to hit you much more softly, slowly revealing its round, rich flavor rather than drown you in grease. (While we're on the subject, mayonnaise is also a great demonstration of acid balance -- many people never realize its primary flavoring is lemon or vinegar.)
What results is a sauce that adds succulence, brightness and voluptuousness to nearly anything, a natural match for lighter items like fish or chicken or vegetables, but I'm not going to stop you if you want to puddle it under a pork chop, either. It's perfectly lovely in its purest form, but the other reason to love beurre blanc is how it behaves as a canvas for any number of flavors you want to throw at it.
Since it's so simple -- really just a reduction of something tasty and tart with a bunch of butter whisked in -- you can modify it easily and drastically by changing up the reduction, or adding different flavorings at the end. Use red wine and a little stock in the reduction instead of white for a heartier sauce. (Red wine actually makes a traditional variant called, appropriately, beurre rouge.) Use something altogether other than wine -- fruit juices mixed with a really nice aged vinegar, for example. (One of my favorite versions, one that brings out the applause, uses apple cider for the reduction.) Or, say, vinegar darkened with soy sauce and sparked with chile paste. Or, to finish the sauce, shower it with herbs. To go in the other direction, give it a little funk by stirring in a tiny bit of mashed anchovy. Or go nuts with your spice cabinet. You get what I'm saying here.
Basic Beurre Blanc
Makes about a pint, which goes a long way (it will probably serve 8 to 12). Feel free to cut this in half, but much less than that becomes a little hard to control because you won't have much liquid to work with.
- 8 ounces dry white wine
- 3 tablespoons good-quality vinegar (white wine is traditional, but I like a nice aged sherry vinegar, even though it gives a brownish color)
- 1 medium shallot, finely chopped
- 1 pound (yes, you heard me right) unsalted butter, cold
- Salt and pepper, to taste (white pepper is traditional, to keep with the color theme)
- Lemon juice, to taste (optional)
- Put the wine, vinegar and shallot into a saucepan big enough for you to fit all the ingredients plus the head of a whisk. (Speaking of which, try to use a smaller whisk; one of those giant balloony ones might miss all the corners of the pot.) Set it over medium-high heat and let it bubble briskly, reducing it to a syrupy consistency (until it's about 2 tablespoons).
- While the liquid is reducing, cut the butter into ½-inch pieces. If it's very cold, let it sit out -- you want it a bit cooler than room temperature when you start whisking it in. But if it's softening or melting, get it back in the fridge or freezer pronto, s'il vous plait.
- When the reduction is ready, remove the pan from the heat and turn the flame down to the lowest setting. Add 6 or so chunks of butter and whisk them in. It should look like it's dissolving into the sauce, making it look creamy, not melting and separating into a yellow, oily slick. If it's doing that, add in a bunch more butter and whisk away. What's happening is that it's too hot and the butter is melting more quickly than you're able to emulsify it into the reduction. Adding more cold butter will help to cool it down.
- When the mixture is looking creamy and all the butter you've added is incorporated, put the pan back on low heat and continue to whisk in the rest, a couple of chunks at a time. (If you're really a star, you can ditch the whisk entirely and just swirl the pan as you add butter. It makes you a little cooler, but I'm not sure it makes the sauce any different.)
- When all the butter is completely incorporated and the sauce looks smooth, season it to taste with salt and pepper and, if needed for perfect balance, a squeeze of lemon or maybe a little more butter. Feel free to strain out the shallots, but I never do.
Holding this sauce is a tiny bit tricky, since keeping it over a flame will break it, and letting it cool completely to room temperature will break it. Usually I'll just keep it on an unused burner on the stove, and the warm air around it as other burners are going will keep it just right. Give it a whisk once in a while to make sure it's still smooth.
Note: If your sauce does break because it's gotten too hot, all is not lost. Pour off the butter that looks oily, and whisk in a splash — say, a teaspoon — of cold water and some more cold butter pieces. It should look like it's coming back together, at which point you can try to reintroduce the poured-off molten butter. Do so carefully, and if it starts to look like the sauce isn't taking it, stop. Don't force it. It won't play well if you do.
If it's gotten too cold and solidified and broken that way, then try chilling it until cold in the fridge. Cut it into small chunks, and whisk it into heavy cream that you've reduced by half.