Dalgona (Sugar and Baking Soda Candy Stamped with a Shape)

Name: Dalgona (Sugar and Baking Soda Candy Stamped with a Shape)
Prep time: 5 min
Cook time: 5 min
Total time: 10 min
Yield: 2 servings
Cuisine: Korean
Ingredients: 4 tbsp sugar; baking soda; neutral oil; 1 stainless-steel ladle; 1 pair wooden chopsticks; 1 flat-bottomed press; 1 shape cutter; 1 sheet baking parchment

Sugar is melted in a ladle, a pinch of baking soda is stirred in, and within seconds it foams up and turns pale. It is tipped out, pressed flat and stamped with a shape. There are two ingredients, sugar and soda, and no acid at all: what makes the soda foam is the heat of the molten sugar. Too much soda and it turns bitter; leave the sugar too long and it runs on towards caramel and turns bitter that way.

Ingredients

2servings

Two pieces
sugar · two tablespoons at a time4 tbsp
baking soda · a pinch on the tip of a chopstick each time; less than 1/8 tsp
neutral oil · the thinnest film, for the press and the cutter
Tools
stainless-steel ladle1
wooden chopsticks1 pair
flat-bottomed press · the base of a small pan or a heavy glass1
shape cutter · a cookie cutter1
baking parchment · dusted with a little sugar1 sheet

Steps

Set everything out first. Dust the parchment with a little sugar and wipe the base of the press and the cutter with the thinnest film of oil. Once the soda is in you have seconds, with no time to look for anything.
Put 2 tbsp of sugar in the ladle over low heat and stir with a chopstick as it melts, from the edges in. When no grains are left and it is clear, take it off the heat before it darkens.
⏲ 2 min
Add a pinch of soda on the tip of the chopstick and stir fast. Within seconds it foams up, turns pale and goes opaque. If it does not rise, touch the ladle back to the heat for a moment as you stir.
⏲ 10 sec
As soon as it rises, tip it onto the parchment. Leave it about 10 seconds for the edge to firm a little, then press it flat in one movement.
⏲ 10 sec
At once, set the cutter in the middle and press lightly, just enough to mark it. Press hard and it cracks there.
Cool a minute and lift it off. Make the second one with the rest of the sugar. Leave the ladle in water and the set sugar dissolves off it.
⏲ 1 min

Tips & Variations

Variations

Dalgona and ppopgi: originally two things. Dalgona was a lump of white glucose melted in a ladle, stirred up with soda and eaten as it was; ppopgi was sugar melted with soda, poured onto a metal plate, pressed flat and stamped with a shape. This page makes ppopgi. Today both are usually called dalgona.
The shape game: the fun is prising the stamped shape out with a needle without breaking it. Pressed too thick it will not come free; too thin and the shape breaks with it.
Regional names: ttigi, jjokja and ttonggwaja among them.
With brown sugar: the molasses gives a darker, deeper sweet. It colours sooner than white sugar, so take it off the heat earlier.

Tips

It rises with no acid at all. Irish soda bread and medovik, which use soda to raise a dough, both give it an acid to react with. The soda bread says "Bicarbonate of soda is a base and makes no gas by itself." Medovik makes honey the acid — "Honey is acidic, bicarbonate of soda meets that acid over heat" — and warns: "Swap in golden syrup or a sugar syrup and it will not foam, and the dough comes out heavy and hard." Dalgona is sugar and soda and nothing else. What makes it rise is heat. Korean Wikipedia's entry for sodium bicarbonate says that when heated it gives off carbon dioxide and water and turns into anhydrous sodium carbonate.
Neither page is wrong. In soda bread and medovik the soda sits in a dough or in warmed honey, and at those temperatures the gas comes from the reaction with acid. The ladle here is somewhere else entirely. Sugar melts clear just short of the point what sugar does marks: "Around 160C it breaks down into colour and bitter aromatics." At that heat the soda breaks down on its own.
A pinch of soda. More is bitter. What is left once the soda has given off its gas is sodium carbonate, and the same encyclopaedia entry notes that soda itself tastes slightly bitter and salty. Add more and it does not rise more; it just tastes bitter and darkens faster.
Taking it off the heat prevents the other bitterness. The gap between sugar turning clear and sugar turning to caramel is short, and the 160C line above is that boundary. Take it off as soon as it melts and add the soda off the heat; go back to the flame only for a moment, and only if it will not rise.
Once it has risen, do not wait. The foam sets as it cools. Tip it out, ten seconds, press, and straight in with the cutter. A beat late and the cutter will not go in and the whole disc cracks.