Sometimes it helps to go back to the beginning. That's what I did while developing my recipe for duck à l'orange. When I told my wife, Kate, that my testing process would put it on our dinner table—again, and again, and again—she looked disappointed. She wasn't excited, she said, because the orange sauce is too sweet for her taste. She's right that it often is, but it really shouldn't be.
Understanding that, though, requires digging deeper than just looking at a bunch of previously published duck à l'orange recipes. It's not enough to simply ape what's out there today; more modern recipes too often feature sugary sauces, at times garnished with additional sweet orange flesh. That's not what duck à l'orange is meant to be. The sauce that's traditionally served with the dish is called sauce bigarade, named for the bitter orange that's meant to flavor it. Because bitter oranges can be hard to come by, most modern recipes substitute sweet orange juice cut with a dose of lemon juice. The problem is that once those sweet oranges are introduced, it's a slippery slope to higher and higher levels of sweetness. Sugar is seductive that way.
The key for any recipe developer working on this recipe is to track down some bitter oranges and make the sauce the way it's supposed to be made first; judging by many of the published recipes I've seen, I suspect that a minority have gone to the trouble. Only after understanding the sauce in its original form can we hope to dial in substitutes like navel orange and lemon appropriately.
But that's getting ahead of things. Let me take a step back to define the dish and establish my goals.
What is Duck à L'Orange?
When I said I went back to the beginning, I wasn't being completely accurate. The beginning beginning takes us out of France and south to Italy. Or, at least, that's one version of the story of the origins of this dish—one that Italians are certainly fond of. According to that history, Catherine de' Medici introduced some proto-duck à l'orange to France in 1533, when she moved there with her retinue of cooks to marry the Duke of Orléans. It's plausible, even if there isn't conclusive evidence to support it, given her other significant introductions to French cuisine (béchamel sauce, onion soup, and more).
In any event, one way or another, the practice of serving duck with an orange sauce established itself in French kitchens, until, over the centuries, the preparation as we know it today became cemented as the classic.
That version is as follows: One roast duck, skin crackling and crisp; alongside or spooned over the top, a brown sauce made from a base of beef or veal stock, flavored with the juice and zest of bitter oranges and sharpened with a sweet-sour gastrique made from sugar and wine vinegar.
When properly prepared, the sauce is thick enough to lightly coat a spoon, has enough gelatin from the beef or veal bones to make your lips sticky, enough acidity to slice through the rich fattiness of the duck, and juuuuuuust enough sweetness to make that acidity pleasant. Kinda like lemonade, but with oranges and meat.
When executed well, it's damned good, the kind of thing that deserves to be the centerpiece of a holiday table, and make you wish Thanksgiving could have been centered around duck instead of a turkey.
Start With the Bird: How to Roast a Whole Duck
Duck à l'orange requires one whole roasted duck. Sure, you can do cute versions that feature only perfectly medium-rare duck breasts, but that doesn't make nearly as beautiful a centerpiece. Plus, it kind of misses a key attribute of the original, which is meat that's been cooked until it's more or less well-done.
Duck is a magical animal in this way. Unlike a chicken, which has delicate white meat that reaches kindling-level dryness north of 155°F, and beef, which is loaded with loins that turn to jerky at high heat, duck is one of those special creatures whose every part is just as delicious served well-done as pink. Any doubters out there about this should remember that one of the greatest duck dishes on the planet, Peking duck, is also served well-done.
Duck handles high heat so well for two reasons. First, the meat all over is on the darker side, giving it a richer, oilier texture that can better withstand the drying effects of high temperatures. Second, and even more important, is the duck's luxuriously fatty skin, which insulates the meat and bathes it in mouth-coating rendered fat, ensuring each bite is unctuous. You can cook the crap out of a duck and as long as you eat it with the skin, it will never seem dry.
And that's really the point—unlike so many other roasts, where nailing a specific internal temperature is your goal, the key to a delicious whole roast duck is getting the skin just right. It should crisp on the outside and melt within, enough of the fat should render away that it doesn't overwhelm the flesh.
This is, in the end, great news, because what it means is that it's really, really hard to ruin a roast duck. Probably the worst thing you can do is under-roast it out of some misplaced fear of overcooking it. If the skin is great, the duck will be, too.
I played around with a few different methods of achieving an ideal roast duck. I blanched the birds in boiling water first, and also tried pricking the skin all over, both steps that can help the fat render more completely. I roasted ducks first at low heat until they were cooked through, then cranked the heat to high to try to crisp the skin right at the end (essentially a reverse-sear approach); I started high and then went low; and I blasted one bird at high heat all the way through. I tried the bird spatchcocked and not. I ate, in short, a lot of duck.
All of the methods worked, but some were better than others. I ended up choosing to do both the boiling-water blanch and the skin pricking. I didn't always find their effects obvious, but I also found no harm, and anything that might assist with rendering the fat under the skin is a plus. (The blanching also helps set the bird into picture-perfect form; the skin tightens in the hot water, and because the duck is buoyant, any potentially asymmetrical effects of gravity are negated. No need for trussing; just dip it.)
My least favorite roasting method of all the ones I tried was starting low and finishing high. In a cooler oven, the skin and fat don't brown and render as well, and the last-minute high heat isn't enough to make up for lost time. This is one case where a reverse-sear just doesn't make much sense.
Of the other methods (high then low, and high the entire time), I had similarly good results. Starting high shocks the skin with heat, so that browning and crisping get going right away and keep on chugging even after the oven temperature is lowered. High all the way is the most aggressive approach, and it produces good results, but I'm less enthusiastic about it because it's also more likely to fill your kitchen with smoke and gives you less room for error.
As for spatchcocking the bird versus leaving it whole, I'm agnostic. Spatchcocking the bird offers some benefits: you get the backbone as scrap, which you can add to the other scrap parts to enhance the sauce; it's slightly faster; and you get better browning and crisping on the skin around the thighs. On the other hand, you get slightly less crisping on the skin over the breast, which is centered in a protective pocket of cooler air (see this article for images of how heat encroaches from the edges of a spatchcocked bird, hitting the breast at the center last); spatchcocking also requires doing (easy enough with poultry shears, but not as easy as leaving the bird whole); and you lose that classic roast duck shape for the table. Since they both work, do whichever way sounds better to you (like I said, duck is forgiving).
Get Saucy: How to Make Sauce Bigarade, the Real Secret to Duck à l'Orange
A roast duck is essential for duck à l'orange, but it's not what defines the dish. The sauce is what puts the orange in it. It's not any old orange sauce, though, it's a specific one—sauce bigarade. Knowing this is the key to getting duck à l'orange right. Not knowing it is what has led to so many sickly sweet versions.
"Bigarade" is the French name of bitter oranges, also sometimes sold as Seville oranges. I can't speak for all parts of the world, but in the United States they're not common. In many places, you can't find them at all. This has led to most recipes calling for a mixture of orange and lemon juice instead, which works—but it helps to know what the bitter-orange sauce is supposed to taste like before trying to fake it with other citrus.
Before getting to the citrus, though, we need to consider the base of the sauce: the stock used to build it.
The Base: A Good Brown Stock
Sauce-making in French cuisine has an interesting history. Back when lavish cuisine was exclusively the domain of the aristocracy, integral sauces—ones made from the drippings of roasts—ruled the kitchens of kings. Such sauces are said to be among the best, since each sauce is built from the essence of the meat with which it's served, but they come with a catch: most roasts don't produce adequate drippings to make enough sauce for the roast.
According to James Peterson in his exhaustive book Sauces, wasteful practices, such as cooking additional roasts just to make more sauce, were a common solution. It was something royalty could afford to do, but not something that translated well to restaurants and hotels, where making enough of a profit to stay open is the name of the game. Plus, building a separate sauce from scratch for each and every roast is impractical in a commercial kitchen.
Stocks were the solution. Using trimmings, bones, and other scraps, chefs could infuse water with layers of meaty flavor, plus get plenty of gelatin from the melted collagen of tough connective tissue. That gelatin is an essential ingredient in sauces, as it creates a rich and lip-sticking texture.
Making the sauce for duck à l'orange allows us to combine the powers of a good stock with the enhanced flavor of an integral sauce by infusing the stock with the duck trimmings.
The first thing you need to know is that there are few shortcuts here. Duck à l'orange is only as good as its sauce, and a good sauce of this sort doesn't come easy. I tried in my testing to work out a method using mass-market stock enhanced with powdered gelatin, a technique we use in many other recipes on Serious Eats, but it fails here. The sauce is too reduced, the flavor too concentrated, for a poor-quality stock to pass itself off as something even remotely edible. The results are, to be clear, disgusting.
Your very best bet is to make a brown stock from scratch. Beef or veal stock is ideal, since those bones give up enough gelatin to make a truly spectacular sauce, and the good news is I've worked out a method using a pressure cooker that turns an all-day process into something that takes just a few hours.
If you don't want to do that, a brown chicken stock is your next best choice; it won't have quite as much gelatin as a good beef or veal stock, so the sauce won't get quite the same body, but it'll still be great. (I like to use a pressure cooker for a brown chicken stock, too, which speeds up the process while loading the stock with as much gelatin and flavor as you're likely to get.)
There is another way that may be available to some, and that is to buy decent beef stock from a local butcher or gourmet store that sells it. It's not uncommon to spot quart containers of these stocks in the freezer section at higher-end stores. But still, that comes with a caveat: It is exceedingly rare for even these upper-end stores to sell truly good stock, which means some doctoring is still in order.
As an example, I recently bought two quarts of house-made beef stock from one of Brooklyn's better local butcher shops. The stock was pale, and the only ingredients listed were beef bones and water. So it wasn't a brown stock made with roasted bones, and it lacked all the aromatics (onions, carrots, celery, garlic, herbs, and more) that a good stock should include. All they did was throw some beef bones in a pot and boil them. I could tell by how the stock gelled at refrigeration temperatures that it had a good deal of gelatin from those bones, and I could smell a real beef aroma—something the boxed mass-market stuff totally lacks—but that was the extent of it. Definitely not good enough to make a classic sauce like sauce bigarade.
My solution was to roast the duck trimmings (wing tips, neck, and even the back if you've spatchcocked the bird) as well as the classic array of aromatics until browned, and then simmered all of that in the pale beef stock to create an improved brown stock.
This is a method you can and should use, even if you're starting with a good quality brown beef or veal stock that isn't in need of any doctoring: by simmering the roasted duck trimmings and additional aromatics in the stock, you're laying the groundwork for a bigarade sauce that's a hybrid, part stock-based and part integral (since it's flavored with some of the duck itself).
Into the Citrus Depths
This is where a lot of duck à l'orange recipes go off the rails. Disconnected from its bitter-orange roots, cooks dose the sauce with too much sweet orange juice, then sometimes add insult to injury by garnishing the sauce with supremes of even more sweet orange flesh.
To get back to the recipe's roots, I tracked down some bitter oranges and made the sauce with them first. It's sad they aren't easier to find, because they make a damned fine sauce. Bitter oranges are, of course, bitter, but they're also sour (hence why they're sometimes called sour oranges). On top of that, they have a complex floral aroma that neither navel oranges nor lemons can deliver.
Some recipes add orange bitters, essential orange oil, or orange liqueur to make up for the lost complexity when bitter oranges aren't used; I experimented with this but didn't love the results—none of those ingredients add the bitter-orange flavor you need, and in some cases they add stuff you don't, like additional sugar or barrel-aged notes.
Another key difference is that the zest, which is added to the sauce as a garnish and to flavor it further, is quite a bit tougher than navel orange zest. In both cases the zest needs to be blanched in boiling water first to soften it and strip away some of its intensity, but bitter orange zest takes a lot longer to get there—at least fifteen minutes, compared to one or two minutes for navel orange zest.
Many recipes that use navel orange and lemon juice in place of bitter orange call for a higher ratio of orange to lemon. But having tasted the sauce made with bitter oranges, I shifted my ratio to a 1:1 combo of navel orange and lemon. It's more sour and less sweet, which is exactly the point. If you can find bitter oranges, though, my sauce recipe will work just as well with those.
La Sauce Gastrique
The sweetness in sauce bigarade isn't meant to come from the orange component. It comes from the gastrique, which is essential to sauce bigarade. A gastrique is a sweet-sour mixture of caramel and wine vinegar, added in small doses to a sauce to flavor it. When done right, the acidity is bright and sharp, but lightly rounded out by the darkened sugar. It shouldn't be cloying or heavy-handed, like many of the sweet-sour sauces we encounter today.
There are two common approaches to making a gastrique, and both are flawed. The first is to put dry sugar into a saucepan, melting it into a caramel (you know, that whole "don't touch it except to brush down the sides of the pot with a wet pastry brush" nonsense?); the vinegar is then added to that caramel once it's done. The advantage to this is that it's easy to judge the caramel browning since it happens before the vinegar is added. The problem is that it doesn't work well on all types of heating elements, and, if you're not careful, some areas of the sugar can burn before it's all melted.
The second method is to mix the vinegar with the sugar, then boil it until enough of the vinegar's water has cooked off to allow the sugar to caramelize. This method is faster, and lowers the risk of scorching the sugar, but it's also incredibly difficult to judge the level of caramelization, since the red vinegar called for in sauce bigarade is dark red, making a visual assessment of the caramel color nearly impossible. It's very difficult to get consistent results this way.
Much, much better is to use the wet technique for making a caramel, which Stella has written about before. To do it, you add water to the sugar first, which wets and dissolves it, speeding up the caramelization process while helping to prevent scorching. The water cooks off as the mixture boils (which, incidentally, you can swirl and stir and otherwise monkey with to ensure even browning, no wet pastry brush needed), and it's clear to the eye when the caramel reaches a nice deep amber color.
At this point, you can add the vinegar in very small additions, gently swirling as you do; it will boil and bubble violently, so take your time to avoid a boil-over. Some of the sugar might seize up a bit, but if you keep swirling, it'll dissolve back into the solution quickly.
I boil the gastrique for a couple minutes longer, just to reduce it slightly, then set it aside until it's time to add it to the sauce.
Finishing sauce bigarade is easy once you have all the pieces in place. Your enhanced stock should be strained of any solids, reduced to about one cup, and skimmed of any fat or scum. Your citrus juice should be squeezed, the zest cut into a fine julienne and blanched. Your gastrique is ready, and you have a couple tablespoons of cold butter at the ready.
Add the citrus juice to the stock and reduce it slightly, until the mixture lightly coats the back of a spoon (nappé, as the French say). Now stir in the gastrique one teaspoon at a time, tasting as you go, until the sauce hits a perfect sweet-sour balance. It should lean sour and have some intensity to it, but be careful—too much gastrique can quickly ruin a sauce.
Whisking constantly, work the butter into the sauce, making sure to keep the sauce below the boil, lest it break. It should be silky and glossy, the butter helping to enrich, thicken, and temper the acidic edge of the sauce even more.
Now add the blanched citrus zest and season the sauce with salt and black or white pepper.
At this, you're done, it's time to eat. It's a savory dish, as it should be. Save the sweets for dessert.