Melt a lump of butter, pulling it off the flame as soon as the soft, pale solid dissolves into a foamy pool. It will taste gentle, milky and vaguely sweet, a dulcet and unchallenging ingredient. Now melt another lump of butter, but instead of turning off the stove as it liquefies, leave it be. In just a few minutes it will transform, turning golden, then ruddy, and finally almost black. At each stage it takes on new a new layer of flavor, gaining a delicious, nut-like intensity as it darkens.
Brown butter: it's the underside of butter, the profound, savory unconscious to butter's creamy, sweet simplicity. As a sauce or condiment, it lends a bold, woodsy flavor and satiny texture. Used in place of regular butter in everything from sauces to sauts to desserts, it can add a startling, unexpected nuance, replacing a muted and delicate taste with something robust and concentrated.
But though browning butter is fairly common technique in restaurants and pastry shops, it's not often used at home. And in fact, brown butter is one of the easiest things to make; the only skill involved is knowing when to turn off the heat.
Brown butter has a long history, especially in France, where it is called either beurre noir (black butter) or beurre noisette (hazelnut butter) depending upon the shade to which it is cooked. True to its name, beurre noisette really does look and taste hazelnuts, while beurre noir, actually a mahogany brown, has a more earthy, coffee-like complexity that verges on bitterness. Larousse Gastonomique dates brown butter back to the 16th century, noting that Rabelais referred to a black eye as "un oeil au beurre noir."
Brown butter's unique character comes from the caramelization of the milk solids found in butter. As butter melts, the milk solids rise to the top in a frothy layer, then sink to bottom of the pan. There, they come into greater contact with the heat, cooking and taking on color. "You can kind of compare melted and brown butter to a piece of white bread and a piece of toast," said Rick Moonen, the chef of Oceana, a seafood restaurant, "the incredible difference in flavor comes from the caramelized sugars."
The darker the color of the milk solids, the more potent the taste, though you never want to overdo it since it can blacken and burn in a matter of seconds. Most chefs advise whisking the butter once it begins to simmer, and keeping a close eye on the bits at the bottom. A white, enameled pot shows off the color best, but any thick pan will do. One thing to keep in mind, says Mr. Moonen, is the temperature of the butter and the pan. A cold knob of butter in a hot pan may cook unevenly, parts of it burning before all of the butter melts. It's better to start with a cold pan and room temperature or cold butter, then to heat them slowly.
Mr. Moonen has another trick, one handy for making copious amounts of brown butter to order in a busy kitchen. "Use your ears," he said, "At first the moisture will boil away and it sounds like sizzling. When it gets quiet, it browns quickly, so then you have to watch it."
When the color reaches the desired shade (anywhere from toasted cashew to chestnut) it's essential to stop the cooking immediately. One method is to add a splash of something cool, like lemon juice, to the pot. Another is to dip the bottom of the pan into cold water. Or, simply decant the finished butter into a heat proof container.
Once you have the basic technique down, improvising is easy. The most basic of preparations is a classic pan sauce. Sharpened with lemon or vinegar and salted with capers, it adds richness and tanginess to lean, mild fish like skate. The acid is paramount. It both enhances the flavor and allays the unctuousness of the fat. And while lemon juice and white wine vinegar are the traditional embellishments, balsamic and sherry vinegar also work well, as does other citrus like orange and lime.
At Citarella, another seafood restaurant, chef Brian Young adds balsamic vinegar to brown butter to sauce seared sea scallops, which he pairs with cauliflower puree and caramelized cauliflower. The different levels of sweetness, from that of the fresh, saline scallops to the mild cauliflower to the sweet-and-tart balsamic vinegar is compelling. Dan Silverman, the executive chef of Union Square Caf, draws on the same balsamic-based combination, stirring in capers and sliced cornichons, and spooning it over shad roe in season. And in his book, Simple to Spectacular (Broadway Books, 2000), chef Jean-Georges Vongerichten devotes a slim chapter to brown butter pan sauces, adding everything from sesame oil and lemon grass to chiles, herbs, and tomatoes.
Although for the most part, most chefs associate brown butter sauces with fish, they can also work on lean meats and vegetables. At Montparnasse, a bistro, chef Philippe Roussel tops filet mignon with plain brown butter to accent the seared flavor of the meat. He also sauts spinach in garlic-scented brown butter as the French antidote to creamed spinach. Similarly, at March, chef Wayne Nish uses brown butter as a seasoning on top of broccoli rabe and endive. "It works very well with bitter vegetables, its richness counterbalances them," he said.
Another bonus of using brown butter in place of regular butter as a seasoning is that, due to its full, heady flavor, you don't need to use as much of it. That's the reason Patricia Yeo, chef of AZ, spoons it over her duck schnitzel in place of clarified butter. "I try not to use a lot of butter," she said, "but when I do use it I use brown butter. It's more complex and interesting"
The Italians, of course, use brown butter on pasta, traditionally winter squash ravioli. Joseph Fortunato, the chef at The Tonic in Chelsea, goes one step further, replacing the olive oil in the pasta dough with brown butter. This may be why his version of winter squash ravioli is one of the city's best. The sauce, simmered with sage, makes a silky blanket that softens the pungency of the herb and underscores the nuttiness of the squash, while the brown-flecked pasta and a sprinkling of walnuts deepens the flavors. A garnish of shaved pecorino is the perfect, salty contrast.
In dessert making, brown butter can add a round fullness, lending the flavor of nuts when there are none, or heightening those already present. Folded into the batter of a madeleine or financier, it contributes a forthright, nutty perfume, resulting in a dainty little cake with a whole new dimension. It's also a terrific medium for sauting fruits, as pastry chef Dalia Jurgensen does at The Tonic. Her pan-roasted caramelized pineapple, cooked in brown butter and honey, is a delectable, burnished ring, a juicy counterpart to the milky, coconut rice pudding served underneath. Plums, apples, pears, and bananas also benefit from a quick brown butter-and-sugar saut, especially with a split vanilla bean stirred into the pan. Spooned over ice cream or pound cake, there is no better sauce.
Although it's not traditional, brown butter makes a fine, full-flavored stand-in for regular butter in tart crusts (both savory and sweet), cookie dough, and even, somewhat strangely, rice krispie treats.
Michael Sullivan, the chef de cuisine at Le Zinc, once even made a brown butter frosting for devil's food cake. It was a huge success, though the inspiration came from an accident. "We tried it because someone left the butter on too long when they were clarifying it, " he said. "We ended up with pounds of brown butter and needed a way to use it." Lucky for them, the options are many.
Sauteed Spinach in Garlic Brown Butter
Time: 15 minutes
5 tablespoons unsalted butter
2 garlic cloves, peeled and smashed
1 1/2 pounds baby spinach, washed but not dried
Salt and freshly ground black pepper to taste
1. In a large skillet over medium heat, melt the butter with the garlic. Let cook until the white foam begins to sink to the bottom and turn a rich nut brown, about 4 minutes.
2. Add the wet spinach to the pan and toss well. Cover the pan and let cook for 2 minutes. Uncover and saut until the spinach is wilted, about 10 minutes. Remove the garlic cloves and season with salt and pepper. Serve immediately.
Caramelized Onion Tart with a Brown Butter Crust
Time: 2 hours plus 4 hours chilling
11 tablespoons unsalted butter
2 tablespoons olive oil
3 Spanish onions, thinly sliced
2 shallots, thinly sliced
2 sprigs thyme or 1/4 teaspoon dried thyme
Freshly ground pepper
1 tablespoon sherry vinegar or to taste
1 1/4 cups all-purpose flour
1/4 teaspoon salt plus additional to taste
3/4 cup crme fraiche or heavy cream
2 large egg yolks
1. In a small heavy saucepan over medium heat, melt 9 tablespoons of the butter. Let cook until the white foam begins to sink to the bottom and turn a rich nut brown, about 7 minutes. Pour the butter through a fine mesh sieve into a measuring cup. You should have 1/2 cup (discard any extra). Refrigerate until the butter solidifies, about 3 hours.
2. Meanwhile, in a large skillet over medium low heat, melt the remaining 2 tablespoons butter with the olive oil. Add the onions, shallots and thyme and season with salt and pepper. Toss well and cook gently, stirring occasionally, until the onions are soft and caramelized, about 1 hour. Add a splash of water to the pan during cooking if the onions look dry. Remove the thyme branches and stir in the vinegar and more salt and pepper. Set aside.
3. In the bowl of a food processor, pulse the flour and 1/4 teaspoon of salt to combine. Cut the chilled brown butter into pieces and add it to the flour. Pulse until the mixture resembles oatmeal. Sprinkle 2 to 3 tablespoons of cold water over the mixture and pulse until it begins to come together. Empty the dough onto a work surface and press it into a disk. Wrap in plastic wrap and chill for 30 minutes.
4. On a lightly floured surface, roll the dough out to a 10-inch round. Fit it into a 9-inch tart pan, folding the excess dough back into crust to build up the sides. Prick dough all over with a fork and wrap in foil. Refrigerate for at least 30 minutes or overnight.
5. Preheat the oven to 375 degrees F. Line the tart shell with foil and fill with pie weights or rice. Bake for 15 minutes, then remove the foil and weights and bake for 10 minutes longer, until the crust is golden. Cool on a rack. Lower oven temperature to 325 degrees F.
6. In a bowl, whisk together the crme fraiche and egg yolks. Stir in the caramelized onions. Spread the mixture in the tart shell and bake until set, about 25 to 30 minutes. Serve warm or at room temperature.
Seared Sea Scallops with Caramelized Cauliflower and Balsamic Brown Butter
Adapted from Citarella
Time: 1 1/2 hours
1 small onion, peeled
1 head garlic, top sliced off to expose the cloves
1 head cauliflower
1/2 cup milk
1 shallot, thinly sliced
1 1/2 tablespoons olive oil
1 stick (1/2 cup) plus 2 tablespoons unsalted butter
1/4 cup balsamic vinegar
1/4 cup white wine vinegar
1/4 cup fish stock
Salt and freshly ground pepper to taste
20 sea scallops
1. Preheat the oven to 400 degrees F. Wrap the onion and garlic separately in foil and roast until soft, about 45 minutes. Let cool, then squeeze the garlic cloves from the skin. Puree the onion and garlic separately in a blender or food processor. Set aside.
2. Break the cauliflower into florets and set aside 4 nice large florets. Thinly slice the remaining cauliflower and place in a pot with the milk, shallot and 1/4 cup of water. Cover and cook over medium low heat until tender, about 20 to 25 minutes. Uncover, raise heat to high, and cook off any excess liquid if necessary. Use a blender or food processor to puree the cauliflower and add salt and pepper to taste. Keep warm.
3. In a skillet, warm the olive oil over medium high heat and add the 4 reserved cauliflower florets. Cook, stirring, until golden brown on all sides. Transfer the florets to a paper towel-lined plate and set aside.
4. Place 1 stick of the butter in a large, non-reactive pan over medium heat and bring to a simmer. Let cook, whisking, until the white foam begins to sink to the bottom and turn a rich brown, about 4 minutes. Whisk in the balsamic vinegar, white wine vinegar, and fish stock. Whisk in 1 tablespoon each of the onion and garlic purees and salt and pepper to taste. Keep warm until needed.
5. In a large skillet over medium-high heat, melt 1 tablespoon of the remaining butter. When the foam subsides, add half the scallops. Cook, turning once, until golden brown on both sides, about 2 minutes per side. Transfer to a plate and tent with foil to keep warm. Repeat with remaining butter and scallops.
6. Arrange the scallops on each of four plates and drizzle with some of the sauce. Spoon some of the cauliflower puree next to the scallops and garnish with the caramelized florets. Serve immediately.