I should have seen this topic coming when I asked my friends on Instagram what kind of science article they’d want to read. The idea that instant coffee could be whipped (quite literally) into something so aesthetically luxurious did intrigue me though. It was never my intention, but I am going to hop on the bandwagon that is Dalgona coffee.
Dalgona coffee originated from India, Macau, and Pakistan, where it was known simply as whipped coffee. It was apparently popularised by South Korean actor Jung Il-Woo, who had it in Macau. He nicknamed it Dalgona due to its resemblance to the Korean honeycomb candy of the same name. It has since become viral on social media because people seem to be able to make a trend out of anything now that they have to stay at home.
The recipe for Dalgona coffee calls for a mixture of instant coffee, sugar, and water to be whisked together in a 1:1:1 volumetric ratio. The procedure reminded me of meringues, and my hypothesis was that Dalgona coffee works similarly. In meringues, egg whites are beaten such that the proteins present are broken down, and this beating incorporates air into the mixture. The proteins form networks around the air bubbles, trapping them, and resulting in a foam being formed. The proteins found in instant coffee can have the same effect. When the mixture is whipped, the air bubbles become smaller and more stable. In addition, the sugar stabilises the air bubbles formed, resulting in a consistency that is thick and frothy. Since this whipped mixture is mostly air, it is light and thus, floats.
Armed with the power of knowledge, I grabbed my ingredients and whisked my coffee mixture for the duration of eight Jay Chou songs. I failed spectacularly.
In my attempt to salvage the situation, I went back to the meringue recipe and realised that making successful meringues required the lack of egg yolks. The fats present in egg yolk bind to the proteins in the egg whites, interfering with the protein network formation. The air bubbles become less stable, and the foam cannot form as well. The 3-in-1 instant coffee powder I used turned out to be the problem. There was 3.5 times as much fat as there was protein in the coffee powder I used. The creamer in the coffee powder contained hydrogenated palm kernel oil, and that probably prevented protein network formation. It is no wonder that stable air bubbles could not form.
In the name of Science, I bought instant coffee that did not contain creamer and tried again. The result?
The mixture did become creamy, but it was not as frothy as I would have liked it to be. I suspect that the ten minutes of whipping time was insufficient to incorporate enough air, or I might have added a little too much sugar and made it too thick. Nonetheless, I was satisfied with my results and it did float on top of my milk. It basically tasted like very sweet milk coffee to me, which should not be surprising since the composition of the ingredients was not exactly altered.
Then, a friend asked me if the same method could work with other drinks, such as Milo. Like any good Science student, I conducted another experiment to test this out.
The Milo mixture became thicker, but it was very likely due to the presence of sugar and water. Milo powder contains fats, either in the form of sunflower oil or vegetable oil. I tried adding more sugar to stabilise the foam, but it did not help the cause at all. In hindsight, I could have whipped it for an extended period to get the same consistency. Perhaps we should just stick to using coffee if we’re feeling a bit lazier.
It was definitely an interesting experience and I did have some fun discussing the science behind it with my sister, who majors in food science. That being said, I wouldn’t do this again since I can get similar-tasting coffee from a can and the workout my arm went through wasn’t worth it. Don’t let anyone judge you, though. Do whatever makes you happy and whatever makes you stay home during this period. Stay home, stay safe!
Written by Nicholas Chang
Illustrations by Lee Ai Cing