by Samin Nosrat
The skin of a roast chicken or turkey will crisp up on its own as long as the bird cooks long enough for the fat to render. Duck needs a little more help, though, since it has a thicker layer of subcutaneous fat to provide the bird with energy for flying and help keep it warm in the winter months. Using a very sharp needle or metal skewer, prick the skin of the entire bird, focusing particularly on the fattiest parts—the breast and the thighs. The holes will allow the rendering fat to escape and coat the skin as it melts, leaving you with glassy, crisp skin. If roasting a whole duck is beyond your comfort zone right now, start with duck breasts. Before cooking, score the skin on both diagonals with a sharp paring knife, leaving behind a pattern of tiny diamonds. The same rendering will occur on a smaller scale, leaving the breasts with perfectly crisped skin.
I’m a stickler for rendering the fat cap on pork chops and rib steaks. I hate getting a nicely cooked steak with a strip of flabby, barely cooked fat running down the side. So either start or finish the cooking process by laying a chop or steak on its side in the pan or on the grill, allowing the fat to render. This might require a little bit of balancing trickery on your part—hold the meat in place with your tongs, or try to cleverly lean the meat up against a carefully placed wooden spoon, or the edge of the pan itself. Whatever you do, don’t skip this step! You won’t regret taking the time to turn that strip of fat into something golden, crisp, and delicious.
Smoke Points
The smoke point of a fat is the temperature at which it decomposes and transforms into a visible, noxious gas. Have you ever added oil into a hot pan for sautéing vegetables and then been distracted by a ringing phone? If you’ve returned to an offensive, smoky scene at the stove, then the oil has surpassed its smoke point. Once, while I was trying to demonstrate the importance of preheating the pan to an intern, another cook approached me with an urgent question. By the time I addressed him and turned back to the pan, it was so aggressively hot that the second I added olive oil, it hit the smoke point, turning the pan black and throwing everyone nearby into a coughing fit. In an attempt to save face, I tried to imply that I’d made the mistake on purpose, and it had been a lesson about smoke points from the start. But, blushing hard before the other cooks, I couldn’t keep a straight face, and we soon all dissolved into laughter.
The higher a fat’s smoke point, the further it can be heated without ruining the flavor of the food cooking in it. Pure, refined vegetable oils such as grapeseed, canola, and peanut begin to smoke around 400°F, making them an ideal choice for high-heat applications such as deep- or stir-frying. Impure fats don’t do as well at extreme heats; the sediment in unfiltered olive oil and the milk solids in butter will begin to reach their smoke point, or burn, at about 350°F, making them well suited for applications where a very high temperature isn’t needed and their flavors can shine, such as oil-poaching, simple vegetable sautés, pan-frying fish or meat. Or, use them for dishes that don’t involve any heating, such as mayonnaise and vinaigrettes.
Achieving Crispness
Crispness results from food’s contact with hot fat and water evaporating from the surface of food. So do everything in your power to keep the pan and the fat hot when seeking a golden crust. Preheat the pan, then preheat the fat. Avoid putting more than a single layer of food into the pan, which will cause the temperature to drop drastically and steam to condense and make food soggy.
Delicate foods especially suffer in these instances. Cooking in fat that’s insufficiently hot will cause food to absorb the oil, resulting, for example, in unappetizingly beige, greasy fish filets, cooked through but not golden. Steaks and pork chops placed in cold fat will take so long to sear that by the time they appear to be perfectly cooked, the meat within will be well-done, rather than medium-rare.
This doesn’t mean you should categorically crank the heat. If the fat is too hot, the outer surface of the food will brown and become crisp before the center has a chance to cook through. Crisp onion rings with crunchy slivers of onion that slip out on first bite and chicken breast with burnt skin and a raw, flabby center both suffer from having been cooked at temperatures that were too high.
The goal with all cooking is to achieve your desired result on the outside and inside of an ingredient at the same time. In this case, it’s a crisp surface and a tender center. Add foods that take time to cook through, such as eggplant slices or chicken thighs, to hot fat, allowing a crust to form. Then, reduce the heat to prevent burning and allow them to cook all the way through. I’ll explain more about how to navigate between different levels of heat in Using Heat.
Once you have achieved crispness, do your best to retain it: do not cover or pile up crisp foods while they are still hot. They will continue to release steam. The lid will entrap steam, which will condense and drip back onto the food, making it soggy. Allow hot, crisp foods to cool off in a single layer to prevent this from happening. If you want to keep crisp foods such as fried chicken warm, set them in a warm spot in the kitchen, such as the back of the stove, until ready to serve. Alternatively, cool the chicken on a baking rack and then pop it into a hot oven for a few minutes to reheat it before serving.
Creamy
One of the great alchemical wonders of the kitchen, an emulsion happens when two liquids that normally don’t like to mix together or dissolve give up and join together. In the kitchen, an emulsion is like a temporary peace treaty between fat and water. The result is tiny droplets of one liquid dispersed in another, resulting in a creamy mixture that’s neither one nor the other. Butter, ice cream, mayonnaise, and even chocolate—if it’s creamy and rich, chances are it’s an emulsion.
Consider a vinaigrette: oil and vinegar. Pour the two liquids together and the oil, being less dense, will float above the vinegar. But whisk the two liquids together—breaking them up into billions of tiny droplets of water and oil—and the vinegar will disperse into the oil, creating a homogenous liquid with a new, thicker consistency. This is an emulsion.
Yet little more than momentary bewilderment will hold together this simple vinaigrette. Left alone for a few minutes, the oil and vinegar will begin to separate, or break. Use this broken vinaigrette to dress lettuce and the oil and vinegar will unevenly coat leaves, tasting too sour in one bite and too oily in the next. In comparison, a well-emulsified vinaigrette will offer balanced flavor in each bite.
When an emulsion breaks, the fat and water molecules begin to coalesce back into their own troops. In order make an emulsion more stable, use an emulsifier to coat the oil and allow it to exist contentedly among the vinegar droplets. An emulsifier is like a third link in the chain, a mediator attracting and uniting two formerly hostile parties. Mustard often plays the role of emulsifier in a vinaigrette, while in a mayonnaise, the egg yolk itself has some emulsifying qualities.
Using Emulsions
Emulsions are efficient tools for enriching plain foods: a knob of butter swirled into a pan of pasta at the last moment, a spoonful of mayonnaise added into a dry, crumbly egg salad, a creamy vinaigrette drizzled over otherwise unadorned cucumbers and tomatoes for a simple summer salad.
Some cooking requires you to make an emulsion. Other times you will be handed an existing emulsion and your only job will be to keep it from breaking. Become familiar with common kitchen emulsions so you can protect their delicate bonds of cooperation.
Some familiar emulsions:
• Mayonnaise and hollandaise
• Vinaigrettes (though some are very temporary)
• Butter, cream, and milk
• Peanut butter and tahini (once you stir in the oil)
• Chocolate
• The ephemeral crema on top of an espresso
Achieving Creaminess: Mayonnaise
Mayonnaise is an oil-in-water emulsion made by slowly whisking tiny droplets of oil into an egg yolk, which itself is a natural emulsion of fat and water. Fortunately, the yolk offers us a little insurance, as it contains lecithin, an emulsifier with one end that likes fat an
d another that likes water. With vigorous whisking, lecithin connects the minuscule amount of water innate to a yolk to the oil droplets and surrounds tiny air bubbles. The two distinct ingredients integrate into a rich, unified sauce.
But mayonnaise—and this is true of all emulsions—is always looking for an excuse to break, or separate into the hostile groups of oil and water once again.
For a basic mayonnaise, measure out—or at least eyeball—the oil before you start. Choose your oil depending on how you intend to use the mayo—for spreading on a BLT or a Vietnamese bánh mì sandwich, use a neutral oil such as grapeseed or canola. For aïoli to serve alongside Tuna Confit in a Niçoise salad, use olive oil. Each egg yolk will comfortably hold about three-quarters of a cup of oil in a stable emulsion. Since homemade mayonnaise is best when it’s fresh, aim to make the smallest amount possible at a time, though any leftovers will keep in the fridge for a few days.
Oil-in-water emulsions always work better when their ingredients are neither too hot or too cold. If you’re starting with an egg straight from the fridge, bring it up to room temperature before you start. If you’re in a hurry, submerge the egg in a bowl of warm tap water for a few minutes to speed things up.
Lightly dampen a kitchen towel and lay it into a small saucepan, then set the mayonnaise-making bowl in it. The wet towel will create enough friction to keep the bowl steady and prevent spillage. Place the yolk(s) in the bowl and start whisking, adding in the oil one drop at a time using a ladle or a spoon. Once you’ve added half the total volume of oil and created a relatively stable base, start to add the rest of the oil in more swiftly. If the mayonnaise grows so thick it’s hard to whisk, add a few drops of water or lemon juice to thin it out and prevent it from breaking. Once you’ve added all the oil, turn your attention to seasoning the mayonnaise to taste.
Follow these rules, and you’ll see that mayonnaise is difficult (but not impossible) to ruin. During one of his cooking lessons with me, Michael Pollan asked me to explain the science at work in an emulsion. I didn’t really know, so I responded, “Magic keeps it together.” Even now that I understand the science, I still believe there’s some magic at work.
Retaining Creaminess: Butter
One of my favorite poets, Seamus Heaney, once described butter as “coagulated sunlight,” which might be the most elegant and economical way to describe its special alchemy. To begin with, it’s the only animal fat made without killing an animal. Cows, goats, and sheep eat grass, a product of sunlight and photosynthesis, and deliver us milk. We skim the richest cream off the top, and churn it until it transforms into butter. The process is so straightforward that kids can make butter by shaking a glass jar filled with chilled cream.
Remember that butter, unlike oil, isn’t pure fat. It’s fat, water, and milk solids all held together in a state of emulsion. While most emulsions are stable in a narrow range of temperatures (just a few degrees), butter retains its solid form from freezing temperatures (32°F) until it melts (90°F). Compare this to what happens when you heat or freeze mayonnaise—it’ll break quickly!—and the magic of butter will become clear.
This explains why butter sweats when left on the kitchen counter on a hot day—the water separates from the fat as it melts. At even warmer temperatures—in a pan over a hot burner, or in the microwave—butter’s fat and water will immediately separate. Melted butter, then, is a broken emulsion, hardening as it cools, never to return to its former miraculous state.
Take care of its emulsion and butter will lend creaminess to everything from jambon-beurre, the classic Parisian ham and butter baguette, to chocolate truffles. The precise temperatures prescribed for butter in recipes are not arbitrary: butter at room temperature is more pliable, allowing air to be worked into it to lighten cakes, or to combine more readily with flour, sugar, and eggs for tender cakes and cookies, or spread evenly onto a baguette, only to be topped with ham. As I’ll explain later, it’s also important to keep butter cold in order to preserve its emulsion and prevent it from interacting with the proteins in flour when making doughs for flaky pastries, including All-Butter Pie Dough.
Julia Child once remarked, “With enough butter, anything is good.” Put her advice into practice by using butter to make another emulsion: butter sauce. Temperature is crucial with butter-water emulsions. The key is to start with a warm pan and cold butter. For a simple pan sauce, after removing a steak, fish filet, or pork chop from the pan, tip out any excess fat. Place the pan back over the heat and add just enough liquid—water, stock, or wine—to coat the bottom. Using a wooden spoon, scrape any delicious crusty bits into the sauce and bring it to a boil. Then, for each serving, add 2 tablespoons of very cold butter into the pan and swirl over medium-high heat, letting the butter melt into the liquid. Don’t let the pan get so hot that the butter sizzles; as long as there is enough water in the sauce, you’ll be fine. Once you see the sauce begin to thicken, turn off the flame and let the butter finish melting over residual heat, but don’t stop swirling. Taste for salt and, if needed, add a squeeze of lemon or splash of wine. Spoon over the food and serve immediately.
The same method works for making butter-water sauces to coat noodles or vegetables. Do it directly in the pasta pan, as long as it’s hot enough and the butter is cold. Make sure there’s enough water in the pan, and swirl, toss, swirl to make the sauce and coat the pasta all at once. Add pecorino cheese and black pepper and you’ve got Pasta Cacio e Pepe, the classic Roman dish that’s even more delicious than macaroni and cheese.
Breaking and Fixing Emulsions
Some emulsions will naturally break with time, and others will break if fat and water are combined too quickly, but the most common way to ruin one is to allow its temperature to swing. Some emulsions must remain cold, and others warm. Yet others must be at room temperature. Heat a vinaigrette, and it will break. Chill a beurre blanc, and it will break. Each persnickety emulsion has its comfort zone.
Sometimes, you seek to break an emulsion, as when you melt butter to clarify it. Other times, it’s a disaster. Heat a chocolate sauce too quickly and it will break into a greasy, undesirable mess that even I wouldn’t pour over ice cream after the longest day. But, as important as it is to be careful with emulsions, ruining one isn’t the end of the world, and you almost always have some recourse.
If the magic holding together your mayonnaise expires and your emulsion breaks, don’t worry! The best way to learn how to fix a broken mayonnaise is to break it once deliberately so you can figure out how to salvage it.
Here’s the mind-bogglingly simple solution: get out a new bowl, but keep the same whisk. If you have only one bowl, scrape out the broken mayonnaise into a measuring cup with a spout or, failing that, a coffee cup, and clean the bowl.
Bring the clean bowl to the sink and spoon in half a teaspoon or so of the hottest water you can coax from your tap.
Using your oily, eggy whisk, start whisking the hot water maniacally, until it starts to foam. Then, treating the broken mayonnaise as if it were oil, add it drop by drop, continuing to whisk with the urgency of a swimmer escaping a shark. By the time you’ve added half of it back, it should start to resemble a proper mayonnaise again, perfect for slathering on a lobster roll. If this fails you, then begin the entire process over with the insurance a new egg yolk provides, and add the broken mayonnaise back in, a drop at a time.
In the future, if, while whisking together any emulsion, you notice things start to head south, keep these tips in mind. First, as soon as you suspect that you are on shaky ground, stop adding fat. If the emulsion isn’t thickening and the tines of the whisk aren’t leaving visible tracks, then for heaven’s sake stop adding oil! Sometimes, all that’s called for at this point is a good strong whisking to bring things back together.
You can also add a few chips of ice along with the first whiffs of doubt. If you don’t have ice on hand, a tiny splash of cold water from the tap will suffice to regulate temperature and keep the peace.
Fla
ky and Tender
Two proteins in wheat—glutenin and gliadin—comprise gluten. When you combine wheat flour and liquid to make dough or batter, these proteins link up with one another into long chains. As dough is kneaded or batter is mixed, the chains develop into strong, extensive webs or the gluten network. The expansion of these webs is called gluten development, and it’s what makes a dough chewy and elastic.
As gluten develops, dough becomes chewier. This is why bread bakers use flours with relatively high protein content, and work hard to knead doughs for long periods of time to create crusty, chewy country loaves. Salt also preserves the strength of the gluten network. (That’s why the mixer strained with effort when I belatedly added the salt to my pizza dough as a young cook at Chez Panisse.) But pastry chefs generally seek tender, flaky, and moist textures, so they do everything they can to limit or control gluten development, including using low protein flours and avoiding overkneading. Sugar and acids such as buttermilk or yogurt also discourage gluten from developing, so adding them early on will tenderize pastries.
Too much fat can also inhibit gluten networks from forming. By coating individual gluten strands, fat prevents them from sticking to one another and lengthening. This is where the term shortening comes from, because the gluten strands remain short instead of lengthening.
Four main variables will determine the texture of any baked good (and some nonbaked ones, such as pasta): fat, water, yeast, and how much the dough or batter is kneaded or worked (see illustration on opposite page). The particular way and degree to which fat and flour are blended together, along with the type of flour and type and temperature of the fat, will also affect a pastry’s texture: