Dalgona Coffee

Like much of the rest of the world, I spent a lot of 2020 holed up at home. My core memories from that year are mostly made up of social distancing, intense hand washing, and cooking through the books that had long sat on my shelf. But there’s one recipe I remember making over and over again that year: dalgona coffee.

Made by whisking instant coffee, sugar, and hot water together until the mixture resembles a fluffy meringue, the sweet beverage dominated social media feeds that year, piquing the interest of millions (including myself) stuck at home. It’s no surprise the drink was such a hit. Dalgona coffee, which theLos Angeles Timesdescribes as “photogenic Instagram-bait,” was practically engineered for virality: It’s aesthetically pleasing, requires just 3 ingredients, and is as much like a magic trick as a recipe. In a moment when most of us couldn’t just wander down to our favorite café for a cup of joe, trying the coffee fad seemed…exhilarating.

Where Is Dalgona Coffee From?

Dalgona coffee exploded in popularity when the Korean actor Jung Il-woo wasfilmedtrying the beverage for the first time at Hon Kee Café in Macau and likened it to dalgona candy, a Korean sweet that tastes like toffee. “When I was in elementary school, they sold burnt sugar candy outside [the] school,” Jung says to the camera. “This tastes like a melted version of that.” Though many people associate the drink with being Korean, its roots are much murkier, as plenty of cultures around the world have their own version of whipped coffee. In India, there’s phenti hui; in Greece, thefrappe; and in Cuba, the café cubano.

The owner of Hon Kee Café, Leong Ham Kon, told theMacau Post Dailyhe picked up the technique for the drink in 1997 from a couple who visited Macau each year to attend the city’s Grand Prix, though he didn’t try his hand at making the beverage until 2004, when Hong Kong actor Chow Yun-fat visited the café. Eager to impress Chow, Leong made him a cup of the hand-whipped coffee. Chow loved it so much he told Leong it was better than some of the coffee he’d had at five-star hotels. Since then, Leong has been serving the beverage—which he reportedly makes by stirring the instant coffee and sugar mixture 400 times by hand!—at his café.

The Science Behind Dalgona Coffee

Let’s start with the basics: Dalgona coffee is a foam. A foam, as Serious Eats contributor Kevin Liu haswritten for us, is the dispersion of gas into a liquid, like beating air bubbles into egg whites to make meringue, heavy cream to make whipped cream, or a mixture of instant coffee, sugar, and water to make dalgona coffee. In the case of meringue, the bubbles are coated and suspended by egg white proteins. In whipped cream, the bubbles are held by the fat molecules of the heavy cream. Those protein and fat molecules act as surfactants, which, as Daniel wrotehere, forms a shell around the bubbles, stabilizing them.

With dalgona coffee, there’s minimal fat and protein. So what’s acting as the surfactant? If you’ve ever seen freshly pulled espresso, you’ve likely noticed the crema, a reddish-brown foam that forms on top of the shot. According to James Hoffmann, the award-winning barista and author ofHow to Make the Best Coffee at Home, roasting coffee beans produces melanoidins, a foaming agent responsible for crema and cappuccino bubbles. In hisdalgona coffee video霍夫曼说,他苏spects these foaming agents act as surfactants—the caveat being that surfactants alone don’t make a perfectly stable foam. Leave espresso out for a few minutes, and you’ll see the crema start to dissolve.

The melanoidin acts as a surfactant by helping to hold the air bubbles we introduce by whipping; the longer you whip, the smaller the bubbles become, resulting in a more stable foam that’s able to hold its shape for longer. But the viscosity of the coffee, sugar, and water mixture is key, too, in helping dalgona coffee maintain its shape. Foams, writes gastronomist Hervé This in his bookMolecular Gastronomy, are “stabilized by increasing the viscosity of its liquid phase (for example, by adding sugar and glycerol).” The thicker the mixture, the slower your drainage. In short, that means it’ll take longer for any liquid to sink—which is what happens when a meringue weeps.

This would explain why most dalgona coffee recipes call for equal parts by volume of instant coffee, sugar, and water. As you’ll see from my recipe below, though, you don’t actually need to use a 1:1 ratio of instant coffee to sugar. You just need enough sugar to increase the viscosity of the mixture. Here, I use 2 parts coffee to 1 part sugar by volume, but I don’t recommend reducing the amount of sugar beyond this.

How to Make Dalgona Coffee

Here are the basic instructions for making dalgona coffee: dissolve instant coffee and granulated sugar in hot water, whisk (either by hand or with an electric mixer) until fluffy and doubled in volume, then dollop it over a glass of milk. While Leong Ham Kon, the founder of Hon Kee Café, makes his dalgona coffee by hand—stirring until it just foams—most people, including myself, prefer the speedier option of using an electric mixer. You can certainly make it by hand, but the resulting foam will be much softer.

Can You Make Dalgona Coffee With Nicer Instant Coffee?

Dalgona coffee calls for instant coffee granules, which make it possible to pack a lot of coffee flavor into the foam without introducing extra water that would thin the viscosity necessary to hold a somewhat stable foam. But instant coffee isn't exactly celebrated for its flavor. Now, though, there are a lot of serious coffee roasters getting into theinstant-coffee space, except with more delicious results.

Curious to see if specialty coffee would foam, Daniel gave my recipe a go with some instant coffee sourced from an artisan roaster. Even after whipping the mixture in the bowl of his stand mixer for 14 minutes, the mixture would not hold a stable foam, quickly collapsing into an un-aerated puddle. “I think we can safely say that specialty coffee won’t definitely foam like basic instant coffee,” he messaged me on Slack.

I can’t say for certain, but I have a hunch about why it may not have worked. Nicer instant coffees are typically freeze-dried, which helps to preserve the oils that give coffee its rich aroma. Just as a meringuewon’t whip as wellif there’s fat in the bowl, it’s possible that the presence of these oils in freeze-dried specialty coffee make it more difficult to whip up. Cheaper instant coffees, on the other hand, are usually spray-dried: coffee is spritzed into hot air, which dries it via evaporation, leaving behind dehydrated coffee granules.

In a paper published in theTea & Coffee Trade Journal, Dr. Terry Mabbett notes that spray-dried instant coffee’s “low-coffee oil content” is what makes it so ideal for foam. While freeze-dried coffee may be more aromatic, the coffee oils present “can quickly stimulate and speed up the collapse of the foaming process.”

That’s not to say that you couldn’t play around in order to make it work, though. It's possible some brands of higher-end instant coffee might work better than others. It's also possible that adjustments to the recipe might optimize any particular brand of coffee. Adding xanthan gum or gelatin, or manipulating the temperature of the coffee mixture, could help specialty instant coffee hold its shape. In his video, Hoffmann does manage to make his dalgona coffee work with nicer instant coffee by leaving his mixture in the freezer for several minutes to lower the temperature, making it more viscous and easier to whip into a foam.

Whether experimenting in order to make one brand of specialty coffee to work is worth it will depend on how important the quality of the coffee is for you. If you’re just looking to make a fun caffeinated beverage that takes fewer than five minutes from start to finish, you’re probably better off just using plain old instant coffee.

除了方便之外,我还认为flavor-based argument in favor of cheap instant coffee: It usually comes from much more darkly-roasted beans, which have a more acrid, burnt flavor. Mixed with lots of milk and sugar, that burnt flavor becomes much more palatable, like burnt caramel… similar to the very dalgona candy Jung Il-woo compared the drink to when he took that first viral sip. Maybe cheap instant coffee is how dalgona is supposed to taste.