Now a key player in Albert Adrià and Grant Achatz's kitchens, the OCOO Double Broiler has the potential to be the next sous vide. But the device has long been a staple in households across Asia.
“Close, but we actually put the bananas in the Korean machine.”
In the main dining room of Albert Adrià’s flagship Barcelona restaurant, Enigma, you guess what you’re eating. For the most part, I was wrong. A table of chefs seated next to me didn’t fare much better. When a stamp-sized frozen bite on the edge of a large, otherwise empty plate turns out to be squab liver paté, it can throw even the best palates for a loop. But this time I was confident. “It’s like black garlic, but with a banana,” I ventured, taking a bite of the jet black mini banana served skin-and-all teetering on the rim of a bowl filled with dark caramel and a swipe of foie gras mousse.
Twelve courses in at that point, I counted our server’s response as a win. How could I guess the involvement of this mysterious “Korean machine,” even if this was its second appearance of the meal?
The Korean machine, it turns out, is not some sort of repurposed lab equipment or Willy Wonka-esque contraption. When I asked to see it while walking through the kitchen on my way to the speakeasy that serves as the final stop in Enigma’s immersive theater-like dining experience, I was surprised to find that it looked like something I have in my condo kitchen back home: an Instant Pot. The OCOO Double Boiler is actually a popular household appliance in South Korea and other Asian countries where it’s primarily used to cook tough roots and herbs like ginseng to produce extracts used in Traditional Chinese Medicine (TCM).
Like the Instant Pot and other similar devices popular in North American homes, OCOO is an electric countertop pressure cooker. But unlike those devices, the OCOO has found its way into many of the top restaurant kitchens in Spain—Disfrutar, ABaC, Mugaritz, and Arzak, among others—and beyond. After eating at Disfrutar, Grant Achatz even brought one back to Chicago to use at Alinea.
OCOO differs from more familiar cookers in a few key ways. There’s more precise temperature control, ceramic inner pots rather than metal, and, most importantly, the namesake double boiler element created by pouring water on the heating plate before sealing the machine.
“The major difference from most similar devices is the way that it uses pressurized steam that is contained between its outer chamber and inner cooking pot,” says Simon Davies, Alinea’s executive chef. “Because of that, the chamber can reach very high temperatures while not burning the product inside. Essentially, anything inside the pot is cooking using its own liquid as a heat source.”
OCOO’s designer derived inspiration from the traditional Korean gamasot—a large cast iron cauldron with a heavy lid that generates pressure within. Gamasot are traditionally used to cook both rice and TCM remedies—but the addition of consistent pressure, steam, and temperature control makes OCOO far more versatile.
A year before Enigma opened, Albert Adrià was in Seoul visiting Mingoo Kang, chef-owner of the two Michelin-starred modern Korean restaurant, Mingles. There, he discovered the OCOO and brought one back to the Enigma test kitchen. Fifteen days later, Enigma’s executive chef, Oliver Peña, headed to Seoul, where he visited Kang to learn more.
Back in Barcelona, Peña got to work testing it out for himself. “We started to put everything in it,” Peña says. “We put crabs, mussels, oysters, razor clams, abalone, everything. Abalone have a lot of muscle, so you can’t chew it, but we put it with a little kombu for two hours and it was soft like a piece of butter.”
The team at Enigma may have tried putting everything in the OCOO, but the chefs at nearby Disfrutar have somehow found even more possibilities. The restaurant now has 14 machines and is the leading force driving OCOO’s adoption by other chefs. Disfrutar has presented the OCOO at numerous international chefs’ congresses, including Madrid Fusión, and Identità Golose in Milan. The restaurant is also working on recipes and videos for both professional kitchens and home kitchens along with 100% Chef, a designer and distributor of high-end kitchen equipment based in Barcelona, OCOO Europe, and the University of Barcelona.
The first OCOO arrived at Disfrutar three and a half years ago as a gift. For six months, it sat mostly unused—until a stage from South Korea arrived. “All the Korean students we get here know the machine before they come,” says Andrés Conde, who heads up the consulting and research arm of the kitchen at Disfrutar. “We started to use the aged egg program and see what’s going on. It’s a maillard reaction. All the sugars are becoming caramel inside.”
When food browns there’s also evaporation, but here Conde notes that all the flavor is retained inside the closed system of the OCOO. And while making something like black garlic ordinarily takes nine to twelve days, in the OCOO it can be done in seven hours. “It’s a new thing,” says Conde. “We have never seen anything similar here.”
Diners at Disfrutar taste the results of the OCOO throughout the meal. There’s black cauliflower cooked for ten hours, served with coconut and lime béchamel, a sequence of almonds that includes some cooked in the OCOO until they’re as soft as chickpeas, a beefy broth that captures all the flavor of txuleta—the famous Basque rib steak made with mature beef—by cooking plancha-seared steaks in the OCOO, a “hare royale” served as a cocktail, and more. And that’s not even including the stocks made in the machine that serve as the backbone of countless other dishes. Recent experiments poised to make the menu include fresh cheese and gluten-free cakes cooked inside the machine.
At Enigma, where Peña has "only" three OCOOs, the machine is used less often but is no less-valued. “I use it for some special dishes,” Peña says. “We get flavor we can’t get with another way of cooking.” Peña especially likes the complexity developed in the OCOO, which leaves diners with a taste of the pure ingredient that lingers long after you finish the dish. The banana is a prime example. There’s the black banana—soft, sweet, and full of concentrated banana flavors—but also the liquid released by the bananas which creates the deep “caramel” pooled below. Peña cooks the bananas for five hours and then leaves them sealed in the machine for another 17 hours of standby time.
“For us, it’s much more important the standby time than the cooking time,” he explains. “With that standby time, you get the oxidation and that power. If you cook it for five hours and take it out, it’s not the same.” The result is banana on banana—foie gras relegated to a mere supporting role.
My first experience with the Korean machine, though, came a few courses earlier as I guessed at the contents of a dish consisting of a few onion petals sitting in a brown sauce. Pickled onions were easy enough to pick out, but the sauce was the more complicated star—earthy, complex, and as gelatinous as any bone broth. “It’s a spoon of umami,” says Peña of this sauce that’s made purely of porcini mushroom extract. “The mushrooms lose their texture, but the juice is kind of like a garum. It’s really special.”
“This machine is reminding me of 1997 when I was in France and I saw my first sous vide machine,” Conde says, reflecting on all of OCOO’s potential uses and budding popularity in professional kitchens today. “Now, we’re trying to put everything inside and step by step understanding more. That’s the fun thing about being a chef.”
Alinea’s Davies, who now counts six OCOOs in his kitchen, also sees a bright future for the so-called "Korean machine."
“We are constantly seeking out new uses for it,” he says. “I don’t know of any other restaurants using the OCOO in North America currently, but I’m sure they soon will.”