A Hamburger Today
The Food Lab: How to Make Peking Duck at Home (From Scratch!)
Describe something to me as golden brown and crisp, and I'm as happy as a lion who's discovered that his cage door is unlocked just before the zoo opens. Add the word "duck" to that phrase, and I'm the same lion who's discovered that not only is his door open, but it happens to be "free admission if your pants are stuffed with ground gazelle day."
And does anything get golden browner, crispier, or duckier than Peking duck? When properly prepared, the deeply flavored skin should crackle and crunch with the slightest touch of your teeth, and the meat (more of an afterthought, really) should be moist, tender, and flavorful. Wrapped in ultra-thin Mandarin-style pancakes with scallions, crisp cucumber, and a smear of sweet and pungent Hoisin or plum sauce,* it's like a Chinese burrito whose flavor is belied by its diminutive nature.
Of course, getting a decent version—even at a restaurant—can be a chore. Places that do do it well generally require at least a day of advanced notice. Why, you might ask? The preparation is intensely complex, that's why.
Here's a basic rundown:
- Day one: Slaughter duck. Dress, eviscerate, and rinse. Remove neck bone without breaking skin. Tie neck skin in knot. Apply maltose/soy sauce coating to skin. Hang overnight to dry.
- Day two: Use straw to inflate duck skin like a balloon to separate from meat. Blanch duck quickly in boiling water to tighten skin and begin rendering fat. Apply more maltose/soy mixture. Hang overnight to dry again.
- Day three: Roast duck while hanging vertically in wood-fired brick oven. Roast until rendered fat from under skin has completely dripped out of duck, basting meat and rendering skin crackly crisp. Serve immediately.
It's hardly an afternoon project, and to be honest, my goal here is not to try and cheat my way to a vastly simpler preparation. I would, however, like to discover a way to streamline the recipe as much as possible, while still achieving the same goals. Should be easy as duck soup, right?
Duck vs. Duck
First order of business: make sure I've got the right duck for the job. Traditionally, the Pekin breed from Nanjing is the duck of choice. With its smalls stature, deep flavor, and relatively low-fat skin, it's the ideal candidate for ultimate crispness (the more fat you've got, the harder it is to render it all out to a crisp state). Luckily, most of the ducks available in this country are variants of that breed. But are all Pekin ducks created equally?
According to Bob Ambrose of Labelle Farms, not so. According to him, the longer a duck takes to grow to full size, the richer the flavor. Chilling is also a factor. Most ducks (and chickens, for that matter) are rapidly chilled after slaughter by dunking them in an ice water bath. At the supermarket, the ducks can contain up to 10% extra water weight, making them less flavorful, and harder to crisp properly.
Air-chilled birds, on the other hand, retain no extra water weight. I know that air-chilling makes a significant difference when it comes to chicken (try a regular Tyson or Perdue chicken against a Bell & Evans and you'll see what I mean), but does the same apply to duck?
I had Bob send me one of his Alina ducks, a French Pekin breed that takes about three weeks longer to grow to full size than the six weeks that a traditional Long Island Pekin duck is allowed to mature. The ducks are also air-chilled.
Straight up, there were some immediate differences. The air-chilled duck (on the left) was dry to the touch, with tight, dark colored skin, while the water-chilled duck (on the right) was pale in comparison, with a sponge-like texture. I roasted the ducks side by side in the same oven with nothing but a little salt and pepper and fed them to nine tasters in a blind taste-test. While both ducks were reasonably crisp, the air-chilled duck was significantly more so. Flavor and texture-wise, it also trounced the water-chilled duck, with a more intense, ducky flavor akin to squab. Out of nine tasters, seven picked the Alina duck as their favorite.
Air-chilled it would be.
Under The Skin
So what's the key to crisp skin? Three different things have to happen.
First, all the moisture must be driven off. Until all the internal moisture is evaporated, it's impossible to get the skin to a sufficiently high temperature to brown properly, which brings us to the second thing: Browning. The skin must brown slowly, developing flavor, and crisping up in the process. Finally, the fat must render and drain. If the liquid fat is trapped in or near the skin, it will quickly become soggy again as soon as it starts to cool. If all three of these criteria are met, what remains is a protein-based matrix packed with the flavorful products of browning reactions.
So the first step to getting really crisp skin is dehydration. Much as I'd like to be able to make Peking duck in a single day, the best way to dry the skin is to allow the duck to air dry, uncovered, overnight in the refrigerator. Here's another trick: Back when I was searching out a method to make the Ultimate Oven-Fried Buffalo Wings, I discovered that applying a coat of baking powder mixed with salt to the skin before allowing it to dry out resulted in extra crispness.
The baking powder accomplishes this goal in two ways. First, it's slightly basic. By raising the pH, browning reactions occur more efficiently. Secondly, the high pH weakens peptide bonds in the skin, creating more fault lines and rendering the skin ultra crisp and crackly. Would applying this same rub to my Peking work the same magic? I answered that question the only way I know how: by doing it. Fortunately, the answer is an emphatic yes
In addition to the salt and baking powder rub, I also applied a mixture of maltose and soy sauce. Available at Chinese supermarkets, maltose is a sugar molecule formed by linking two glucose molecules (regular sugar is made with a glucose molecule and a fructose molecule). Unlike table sugar, it doesn't granulate, making it easy to spread over the duck. It is, unfortunately, really sticky, messy stuff. The key to working with it is to get your hands wet and to pick up handfuls of it rapidly. Try microwaving a small amount of it along with soy sauce for an easily spreadable syrup you can then rub over the duck with your bare hands. By the time the maltose had time to dry overnight, the duck had taken on a tanned, burnished look that cooked to the familiar deep mahogany color in the oven.
I tried using sugar syrup, maple syrup, and honey as well in case you can't find maltose. Honey was the best substitute, though it was a little sweeter, due to the addition of fructose.
The next key to crisp skin is fat rendering. While heat alone will cause fat to render, unless that fat has some means of draining away, it's no use. This is accomplished by two means. First, the skin is inflated via a straw inserted into the duck cavity. This causes it to pull away from the meat, giving it a channel to drip out of. Second, the duck is cooked by hanging vertically in a hot oven. As the fat renders, it drips out and away from the bottom cavity of the duck, leaving the skin crisp and relatively fat-free.
In order to get rid of the stretch marks caused by the inflation, the ducks are dipped in boiling water briefly, which quickly tightens the skin back up (The channels for rendering fat between the skin and meat still remain).
So how does one replicate these steps at home?
The first part is easy: Rather than inflate the duck (I tried it with no success with a bicycle pump), just pull the skin away from the meat using your fingers and the handle of a wooden spoon. I discovered that really, the most important part is getting the skin away from the breast meat, and from around the joint where the thigh meets the body. It's really very easy to do—just stick your fingers in there and slowly work your way through the cavity.**
For the boiling phase, I wanted to figure out a method that wouldn't require me to lug out the lobster pot. My five-quart stock pot is not quite big enough to dunk a whole duck into. So rather than bring the duck to the water, why not just bring the water to the duck, I thought?
I placed the duck on a rack (yes, it's an IKEA dish rack) in the sink and simply poured the hot water over it, making sure to get it on all sides and inside the cavity. The skin immediately shrunk and tightened around the duck, just like my latex superman suit does when I sit too long in the tanning booth.
Traditionally, the duck needs to be air-dried a second time before entering the oven, but here's what I was thinking: that water is boiling hot, and most of it goes straight down the drain into the sink. Surely, whatever's left should evaporate fast enough that it won't have time to be re-absorbed into the duck skin, right? Indeed it does.
By weighing the duck at all stages in the process, I found that during the overnight rest, it loses about 10% of its weight through moisture loss. If I follow the prescribed method and allow the duck to rest the second night after boiling, it ends up losing only an additional 1% of its weight—hardly worth the fuss, I think. Roasting the duck immediately after pouring boiling water over it confirmed this suspicion: The second rest makes very little difference to the finished product.
So what about roasting it vertically? My thoughts immediately gravitated to beer cans (as they are wont to do). Specifically, beer can chicken.
If you're not familiar with the method, it involves jamming a chicken on top of an open, half-drunk bottle of beer, then chucking the whole thing on the grill. The idea is that the beer will slowly steam, keeping the chicken meat moist and flavorful while simultaneously allowing the chicken to cook evenly from all sides.
Like many good-sounding ideas, this one is totally bunk. To prove it, I cooked three chickens side by side in the same oven. One was stuck on a beer can half-full of beer, the second was stuck on a beer can which I had emptied and re-filled with dried beans (to offer the weight with none of the liquid), and the third was jammed on a can that I filled with the most revolting liquid I could think of: Lipton's Brisk Iced Tea.
After roasting, I carefully removed the cans and fed them to new Serious Eats intern Carly in a blind tasting. Asides from the small part of the chicken which I had accidentally poured beer on while removing the bottle, the three were completely indistinguishable, both in flavor and in texture. Weighing the pre and post cooking confirmed that moisture-wise, all three birds lost exactly the same amount, regardless of whether there was liquid or not inside the can.
Moral: Next time you cook a beer can chicken, drink all the beer first and fill up that can with water. You'll be saving beer, which is always a noble goal.
So what's the real advantage of cooking on a beer can? Positioning. By keeping the bird vertical, just like it is in a traditional oven, the fat and juices drip out the bottom as it cooks, leading to perfectly rendered, lacquered skin.
Wrapping it Up
Now that I had all of my ducks in a row, the only step remaining was to make the Mandarin pancakes. No real innovation here, as the method is already so cool as is.
The idea is that by using a rolling pin, you can only get a flour dough rolled out so thin. But rather than rolling out one ball of dough at a time, if you instead stack two balls and roll them together, you can get each on down to half the thickness you'd be able to otherwise.
The only trick is getting them to be easily separate-able post-cooking. You accomplish this by brushing the top of one with a bit of sesame oil before stacking the second on top of it. The oil not only keeps them separated like layers of puff pastry, but it gently flavors them with its aroma as well.
The dough is made with a standard wonton-style hot water dough. Adding boiling water to flour helps develop gluten really rapidly, creating a silky smooth dough that's a cinch to roll out and a pleasure to work with. After rolling, they just require a quick stop in a hot skillet, where they puff up and turn spotty brown.
Afterwards, all you've gotta do is...
... gently split them apart. If you're really lazy, you can just use flour tortillas. I've been to restaurants that do it. Not good restaurants, but restaurants nonetheless.
As for the garnishes, cucumber and scallion, both sliced thin are a must. Hoisin sauce is the traditional condiment, but it's the middle of plum season right now, so how could I resist making a quick and easy plum sauce? To deepen the flavor and add some savory notes to the beautiful Italian prune plums I bought from the farmer's market, I based my sauce on a dark caramel gastrique, adding a splash of soy sauce, chili, ginger, and vinegar to the mix.
So tell me seriously: after all that, can you think of anything you'd rather be eating right now than a crispy Chinese duck soft taco?. I've gone through a half dozen ducks this week working on this recipe, and I still am craving it...
The only part of the Peking duck that's missing now that I don't have to go out to a restaurant to get it is the bill,*** and that's the only part I could live without!
*I understand the gringo blasphemy of using plum sauce, but it's plum season, and what the heck—it's delicious.
**um... that's what she said?
***sorry for the bad joke. Stupid puns just quack me up.
About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.