Salt, Fat, Acid, Heat

by Samin Nosrat

  Short doughs are the epitome of tenderness, crumbling and melting in your mouth. Here, flour and fat are blended together intimately, resulting in a smooth, homogeneous dough. Many of the shortest recipes, such as shortbread cookies, call for very soft or even melted butter, in order to encourage this now fluid fat to quickly coat individual flour particles, preventing gluten webs from forming. These doughs are often soft enough to press into the pan.

  Rather than crumbling, flaky doughs break apart into flakes when you take a bite. Think of classic American pies and French galettes, with crusts sturdy enough to hold up to a mile-high pile of apples or juicy summer fruits, but delicate enough to produce thin, uneven flakes when sliced. To create that strength, some of the fat is worked into the flour, and a minimal amount of gluten is developed. To achieve the signature flakes of a perfect pie or galette crust, the fat must be very cold so that some of it can remain in distinct pieces. Roll out a properly made pie dough and you’ll see the chunks of butter. When you slide the pie into a hot oven, the cold pieces of butter, entrapped air, and steam from the water released by the butter, all push apart the layers of dough to create flakes.

  The flakiest pastries are made with laminated doughs. Picture the flakes on your plate (or shirt) after you’ve eaten a classic puff pastry, such as a cheese straw, palmier, or a strudel. It’s a mess! A pile of gorgeous, glassy shards! To achieve this texture, a flaky dough is wrapped around a large slab of butter. This dough-and-butter sandwich is rolled out and then folded back upon itself in a process called a turn. Classic puff pastry, when turned six times, will have precisely 730 layers of dough separated by 729 layers of butter! Upon entering a hot oven, each one of those distinct layers of butter will turn to steam, creating 730 layers of flakes. It’s crucial, when making laminated doughs, that the fat and workspace remain cold so the butter does not melt, though the butter must be soft enough to roll into a slab.

  Yeasted doughs, kneaded to develop gluten, and then treated in this way, can yield laminated breads that exist at that precarious intersection of chewiness and flakiness, including croissants, Danishes, and the Breton specialty called kouign amann.

  Achieving Tenderness: Shortbread Cookies and Cream Biscuits

  Shortbread cookies should be tender, with a fine, sandy crumb. This texture is the result of incorporating fat into flour early in the dough-making process. My favorite shortbread recipe calls for butter so soft it’s “spreadable like mayonnaise” so that the fat can readily coat flour particles and keep gluten strands from developing.

  Use any soft or liquid fat including cream, crème fraîche, softened cream cheese, or oil to coat flour and achieve tender textures. In classic recipes for cream biscuits, cold whipping cream functions as both the fat and the liquid binder, quickly coating the flour and obviating the need for additional water to develop the gluten network.

  Achieving Flakiness: Pie Dough

  Guided by lore almost as much as science, the rules of making flaky pastry appeal to my old-wives’-tale-loving heart. Stories of pastry chefs landing jobs due to their cold hands are commonplace since it’s so important to keep the fat for flaky pastry dough chilled. While there’s little evidence to prove that rumor, there’s plenty to support pastry chefs’ compulsion to keep everything cold: they work on cool marble countertops and freeze their mixer bowls and metal tools. One pastry chef with whom I worked for years even insisted on making her doughs in a freezing-cold kitchen. With a sweater and puffy vest layered over her chef’s coat, she’d get to work two hours before anyone else, then rush to mix her doughs before the rest of us arrived and lit the ovens, stove, and grill. She made every decision with temperature in mind, and it paid off—her pastries were ethereally flaky.

  Cold-handed or not, consider temperature when you seek flakiness to create layers of developed gluten interspersed by pockets of fat. The warmer, and hence softer, your butter, the more readily it will combine with the flour. Because fat inhibits gluten development, the more intimately the two ingredients combine, the more tender—not flaky—a dough will be.

  To prevent gluten from developing, keep butter cold. This will protect the delicate bonds of its emulsion while you mix and roll dough. Butter contains about 15 to 20 percent water by weight. If butter softens and melts as it’s worked into the dough, its emulsion will break, releasing that water. Water droplets will bind with the flour, developing into long gluten strands that will cause the dough’s delicate layers to stick together. If they’re stuck together, they can’t steam apart and flake as they bake. The pastry will emerge from the oven chewy and elastic.

  Vegetable shortening (Crisco, for example) is more forgiving of rising temperatures than butter and will remain in solid form even in a warm kitchen, but it just doesn’t taste as good. By the time it reaches body temperature, butter melts away, leaving behind its rich, satisfying flavor as the tongue’s lone souvenir. In contrast, the same chemical qualities that make shortening more stable at warm temperatures keep it from melting away at body temperature, leaving an unpleasant, plasticky residue on the tongue.

  I prefer not to sacrifice flavor for the forgiveness that shortening offers. There is a trade-off: certain measures must be taken to achieve a buttery pie crust flaky enough to shatter at the lightest touch of a fork. At home, chill the diced butter, flour, and tools in the freezer before you start, in order to encourage the butter to remain in distinct chunks even as you work it into the dough. Work quickly to reduce the threat of its softening. Don’t overmix. And finally, ensure that the dough spends plenty of time chilling in the fridge between the steps of mixing, rolling, assembling, and baking. I find it easiest to make pastry dough in advance and keep it tightly wrapped in the freezer, where it can stay for up to 2 months. That cuts out the most time-intensive step, freeing me to make and bake my pie when the fancy strikes.

  It’s important to slide the chilled, assembled pie directly into a preheated oven. In a hot oven, the water contained in the butter will quickly evaporate. The steam will push apart layers of dough as it expands with heat, yielding the flakes we so prize. If the oven’s not sufficiently hot, the water won’t evaporate and the crust won’t set before the filling seeps in, and the pie will emerge from the oven disappointingly soggy.

  Achieving Flakiness and Tenderness: Tart Dough

  Prone to bouts of overindulgence at the farmers’ market, I tend to find myself with more produce at any given moment than I know I can use up. (You try saying no to ripe Santa Rosa plums, perfectly sweet-tart nectarines, and juicy boysenberries, which always come into season on exactly the same day!) With an understanding of the science of fat, my friend Aaron Hyman sought to develop a tart dough that’s structured yet delicate. His ideal dough would stand up to mounds of juicy summer stone fruit but still yield flaky shards when bitten. He wanted a crust that would be both flaky and tender. And I wanted a crust that I could bake anytime I had extra fruit on hand.

  First, he thought about how to achieve flakiness. He decided to keep everything cold, use large chunks of butter, and mix the dough just enough to form a small amount of gluten for the flaky layers. Then, to achieve tenderness, he selected liquid fats to bind the dough—cream and crème fraîche—and to coat the remaining loose flour with fat to prevent further gluten development.

  Aaron’s method is foolproof. I’ve always struggled with pastry dough, but his recipe leads me to success every time. With Aaron’s Tart Dough in the freezer, a regal dinner is always within reach. Stockpile several disks of dough for the moment when you want to invite friends over and have little more in the pantry than a basket of aging onions, a Parmesan rind, and a can of anchovies. Or when you realize you’ve committed to bringing dessert to a party but doubt you have the time to make anything special. Or when you go a little overboard at the farmers’ market. Tart dough is the key to making something out of nothing.

  Tender Cakes

  For years I was disappointed by almost every single cake I tasted, whether I’d baked i
t myself or ordered it in a restaurant or bakery. I dreamed of a cake that was moist yet flavorful. So many cakes were one or the other: store-bought cake mixes yielded the texture I was after but were relatively flavorless, and cakes from fancy patisseries were rich in flavor but often dry or dense. I figured it was an either-or situation. And I resigned myself to it.

  Then I tasted a chocolate birthday cake so moist and rich that I nearly fainted from delight. For days, that slice of cake haunted me, so I begged my friend for the recipe. She called it Chocolate Midnight Cake, for how darkly rich it was, and when she shared the recipe, I noticed it was made with oil and water rather than butter. When I tasted the Fresh Ginger and Molasses Cake at Chez Panisse for the first time a few months later, I was stunned by its perfectly moist texture and deep, spicy flavor. I begged for its recipe, too, and noticed that it was eerily similar to my friend’s.

  There was something to these oil cakes. I flipped through my mental recipe box and realized that many of my favorite cakes, including classic carrot cake and olive oil cake, are made with oil instead of butter. Even cake mixes, which produce the ideal texture I’d been trying to emulate, direct you to add oil. What is it about oil that yields such moist cakes?

  Science holds the answer. Oil efficiently coats flour proteins and prevents strong gluten networks from forming, much like soft butter does in shortbread. Gluten development requires water, so this oil barrier significantly inhibits gluten formation, leading to a tender, rather than chewy, texture. As an added bonus, less gluten means more water in the batter, and, ultimately, a moister cake.

  Once I discovered the secrets of oil cake, I could anticipate the qualities of a particular cake without even trying the recipe. If oil was listed among the ingredients, I knew the recipe would yield the signature moist texture I loved so much. But there were times I craved a buttery cake, too. Rich flavor, rather than a moist texture, took priority in cakes I wanted to enjoy in the afternoon with a cup of tea, or serve to friends at brunch. Emboldened by my discoveries about texture, I began to wonder if I could make a better butter cake. The answer lay not in treating butter like oil and melting it, but rather in capitalizing on butter’s incredible capacity for lightness.

  LIGHT

  Lightness might not be the first quality you associate with fat, but its remarkable capacity to entrap air when whipped allows it to act as a leavening, or raising, agent in cakes and transform liquid cream into billowy clouds.

  Some classic cakes have no chemical leavening—that is, baking soda or baking powder—and rely entirely on whipped fat for their cloudlike structure. In pound cake, whipped butter and eggs do all the work of leavening. In génoise, a type of sponge cake, whipped eggs, whose fatty yolks entrap the air and protein-rich whites surround air pockets, allow the cake to rise. This is the only leavener. There is no baking powder, no baking soda, no yeast, and not even any creamed butter to help this cake rise! It is miraculous.

  Achieving Lightness: Butter Cakes and Whipped Cream

  When seeking rich flavor and a fine, velvety crumb, make a butter cake (or chocolate chip cookies) but take care to aerate this fat by creaming, or whipping, butter with sugar to trap air bubbles for leavening. Typically, cool room-temperature butter is beaten together with sugar for 4 to 7 minutes until the mixture is light and fluffy. When done correctly, the butter will act as a net, entrapping millions of tiny air bubbles throughout the mixture.

  The key is to work air in slowly, so that many consistently tiny bubbles form and you don’t create too much heat through friction. It might be tempting to crank up the mixer so you can get the cake into the oven sooner, but trust me—that’ll take you nowhere good, fast. I speak from experience. The road to this chapter is lined with dense, fallen cakes.

  As you mix, monitor the butter’s temperature; remember, butter is an emulsion and if it gets too warm, it will melt and the emulsion will break or it simply won’t be rigid enough to continue trapping air. You’ll lose all the air you worked so hard to entrap. If butter is too cold, air won’t be able to get in—not evenly at least—and the cake won’t rise straight up.

  And if fat isn’t properly aerated, chemical leavening won’t make up for it. Baking soda and powder don’t introduce any new air bubbles into a batter. They simply help expand, via the release of carbon dioxide gas, air bubbles already in place.

  Incorporating ingredients delicately is important for the same reason—if you go to great lengths to whip air into your fat, then carelessly combine the cake’s dry and wet ingredients, all at once, you’ll lose all of the air you whipped up. This is where folding, the technique of gently combining aerated ingredients into nonaerated ingredients, becomes important. Try to fold using light movements with a rubber spatula in one hand, while spinning the bowl with the other hand.

  Though the chemistry behind whipped cream is slightly different than that of whipped butter—it must be very cold, to begin with—the concept at work here is the same: fat surrounds air bubbles. As cream is whipped, solid fat droplets in the liquid break open and join together (remember that cream is a natural emulsion). Overwhip cream and the fat droplets will warm up and continue to stick to one another, making the cream unappetizingly chunky. Whip it further, and cream’s emulsion will break, yielding a watery liquid—buttermilk—and solid fat—butter.

  USING FAT

  Only on the most special occasions do Persian meals end with dessert, so we never did much baking at our house. Plus, Maman, a health fiend, denied us excess sugar at every turn (though that did little more than encourage my brothers and me to develop fervent sweet tooths). If we wanted cookies or cake, then, we had to make them ourselves, and Maman did her best to ensure it’d be an uphill battle the whole way. She didn’t equip the kitchen with either a stand mixer or a microwave for softening butter, and she stored all the extra butter in the freezer.

  When it hit, the craving for cookies or cake was always urgent. I was never patient enough to wait for frozen butter to come up to room temperature, as every single recipe commanded. And even if I did somehow summon the discipline required to wait for butter to soften, without an electric mixer to help cream it, my cookie dough was always a mess—somehow completely overworked and undermixed at the same time, with huge pieces of unincorporated butter. As a typical teenage know-it-all, I knew I was way more clever than any recipe writer. So I figured I could just melt the butter for my baking on the stove and forgo the softening and creaming processes completely. Melted butter was a heck of a lot easier to stir into cookie dough with a wooden spoon, after all, and it sure made cake batter nice and pourable.

  What I didn’t know then was that by melting the butter, I was destroying any chance I had at working air into it. My cookies and cakes always emerged from the oven disappointingly flat and dense. At an age when my primary goal in baking was to eat something—anything!—sweet, this was a minor problem: my brothers and I hungrily gobbled up whatever came out of the oven. As an adult with a slightly more discerning palate, I’m going for more than just a hit of sugar. I want my desserts—and, frankly, everything I cook—to be uniformly delicious, with the ideal texture and flavor. You probably do, too. All it takes is a little forethought.

  Layering Fats

  Since fats have such a powerful impact on flavor, most dishes will benefit from the use of more than one kind. This is what I call layering fats. In addition to considering the cultural appropriateness of a particular fat, think about whether it will harmonize with the other ingredients in a dish. For example, if you’re planning to finish a fish dish with butter sauce, use clarified butter to cook the fish so that the two fats will complement each other. Pair blood oranges with creamy avocado in a salad, then drizzle everything with agrumato olive oil to amplify the citrus flavor. For perfectly crisp waffles, melt butter to add to the batter, but brush the hot iron with fat that’s rendered out of the breakfast bacon.

  Sometimes you’ll need to use multiple fats to achieve different textures within a single
dish. Deep-fry crisp pieces of fish in grapeseed oil, and then use olive oil to make a creamy Aïoli to serve alongside it. Use oil to make a supremely moist Chocolate Midnight Cake, then slather it in buttercream frosting or softly whipped cream.

  Balancing Fat

  As with salt, the best way to correct overly fatty food is to rebalance the dish, so the solutions are similar to when you oversalt: add more food to increase total volume, add more acid, water it down, or add starchy or dense ingredients. If possible, chill the dish, let the fat come to the surface and solidify, then skim it off. Alternately, lift food out of a very greasy pan and dab it on a clean towel, leaving the fat behind.

  Foods that are too dry, or need just a bump of richness, can always be corrected with a little olive oil (or other appropriate oil), or another creamy ingredient such as sour cream, crème fraîche, egg yolk, or goat cheese to improve the texture and get the flavor right. Use vinaigrette, mayonnaise, a soft, spreadable cheese, or creamy avocado to balance out dryness in a sandwich piled high with lean ingredients or built atop thick, crusty bread.

  Improvising with Salt and Fat

  Follow the tenets I outline in How Fat Works to achieve whichever texture you’re after, then refer to The World of Fat to guide you in evoking the flavors of wildly different places. Choose to pan-fry Finger-Lickin’ Pan-Fried Chicken, for instance, in clarified butter for a classic French flavor. If you’re craving an Indian-inspired meal and want to dig into that jar of mango chutney in the refrigerator door, change the cooking fat to ghee. If it’s a Japanese chicken cutlet you’re craving, use a neutral oil studded with a few drops of toasted sesame oil. In all of these cases, the fat must be sufficiently hot to swiftly lead to browning and deliver a crisp exterior.