The flat white turned up in Australia or New Zealand sometime in the 1980s. Both countries claim it, neither can prove it, and the argument has been going on long enough that it’s now part of the drink.
Here’s what’s in the cup. A shot or two of espresso, then steamed milk poured over it, in a cup around six ounces. The milk is steamed so the bubbles in it are tiny — small enough that it pours like paint rather than sitting on top like a hat. That’s the bit people mean when they say “microfoam,” and it’s the only genuinely technical thing about the drink.
So how is it different from a latte?
Mostly size. A latte is the same two things in a bigger cup, so there’s more milk around the same amount of coffee, and it tastes milkier and softer. A flat white puts the same espresso in less milk, so the coffee comes through harder.
If you’ve ever ordered a latte and thought this is quite nice but I can barely taste the coffee, you were about ninety seconds away from working out that you wanted a flat white.
And a cappuccino?
A cappuccino has more air in it. The milk gets whipped up into proper foam, so you end up with a light, pillowy top and less actual liquid milk underneath. A flat white deliberately doesn’t do that. Same ingredients, different amount of air, completely different drink in the mouth.
A useful way to hold all three: latte is the milkiest, cappuccino is the foamiest, flat white is the coffee-est. Nobody at the counter will think less of you for it.
Does it have more caffeine?
Usually about the same as a latte, because the caffeine comes from the espresso and both drinks tend to get the same number of shots. It tastesstronger, which is a different thing, and which people mix up constantly. If you actually want more caffeine, ask for an extra shot rather than a smaller cup — more on that in how much caffeine is in a cup of coffee.
Should you order one?
If you like coffee with milk but find lattes a bit washed out, yes. If you like the foam, get a cappuccino. If you want it to last longer, get the latte. That’s genuinely the whole decision, and anyone who makes it more complicated than that is enjoying themselves at your expense.
The full board is over in every drink on the board, explained — including the ones nobody ever admits to not knowing.