Why is my dalgona not whipping?
The most common issues are not using instant coffee, having the ratio too far off, or just not whipping long enough. Dalgona works best with instant coffee (or instant espresso powder) plus sugar and hot water to trap air and hold it. Brewed coffee usually will not whip reliably into stiff peaks.
Quick fixes: use hot water (just off the boil), switch to a narrower bowl, and keep whipping. Some instant coffee brands take longer than others, especially instant espresso powders.
Do I need granulated sugar, or can I reduce it?
Granulated white sugar is the most reliable for structure. You can reduce sugar a little, but the foam will be less stable and can deflate faster. If you want it less sweet, an easy move is to use less topping per glass and keep the milk unsweetened.
Can I use brown sugar?
Yes, but expect a slightly looser foam and a more caramel-like flavor. It can still whip, but it usually takes longer and will not be quite as stiff.
Can I use a sugar substitute?
Proceed cautiously. Some substitutes do not create the same stable structure. If you want to try one, start with a granulated 1:1 blend labeled for baking, and be prepared for softer peaks. If it will not whip, switch back to regular sugar or use a small amount of regular sugar to help it along.
Can I make it without a mixer?
Yep. A hand whisk works, but plan on 8 to 12 minutes of steady whisking. It is doable, just a workout.
Is dalgona coffee safe for kids?
Because it is concentrated coffee, it can be a lot of caffeine for kids. If you want a kid-friendly version, use decaf instant coffee or make a cocoa whip using cocoa powder and heavy cream instead.