We spent four years making cold brew and getting written about for it, so treat what follows as informed but not neutral. The honest version is that both of these are good and they are good at different things.
Iced coffee
Hot coffee, brewed normally, then cooled down — usually by pouring it over ice. That’s it. The heat does its work first and the cold happens afterward.
Because it was brewed hot, it keeps the brightness and the acidity that hot brewing pulls out. It tastes like the coffee it came from. It also tastes weaker as the ice melts, which is why the good version is brewed stronger to begin with, and why the bad version tastes like a rumor of coffee by the bottom of the cup.
Cold brew
Never heated at any point. Coarse grounds go into cold water and sit there for around a day, and then the whole thing gets filtered. Time does the job that heat usually does.
Cold water is much worse at dissolving things than hot water, which turns out to be the entire point. The compounds that read as sharp and bitter come out reluctantly in the cold, so what you get is rounder, sweeter, and noticeably less acidic. It also doesn’t get weaker as it sits, because it was never hot enough to be watered down by melting ice in the first place.
The trade is that you lose some of the bright, fruity notes. A delicate, floral coffee brewed cold can taste like it’s been filed down. That is a real cost and people who sell cold brew tend not to mention it.
Which has more caffeine?
Usually cold brew, but not for the reason people think. It’s not that cold water extracts more caffeine — it’s that cold brew is normally made as a concentrate, using far more coffee per unit of water, and often served without being diluted as much as it should be. Compare like for like and the gap mostly closes.
What about nitro?
Nitro is cold brew with nitrogen gas pushed into it, poured from a tap. The gas makes tiny bubbles that give it a thick, soft texture and a head like a stout. It’s the same coffee underneath. Whether the texture is worth the surcharge is a matter of taste, and we are not going to pretend to be above enjoying it.
So which should you get?
If the coffee is something special and you want to taste what makes it special, iced. If you want something smooth you can drink for an hour without it turning bitter or watery, cold brew. If you drink your coffee with a lot of milk and sugar, cold brew, because the smoothness survives everything you’re about to do to it.
Ours is two ingredients — coffee and filtered water, coarse ground, twenty-four hours in a cold room, filtered once. It comes back in 2027. In the meantime we are selling the beans, which is where this company started anyway.