The Korean shorthand Ah-Ah refers to an iced Americano, a drink that has become closely associated with contemporary café routines. Its appeal includes convenience, a recognisable order and the sensory contrast of espresso meeting ice. The source discusses its popularity even in cold weather; that is a cultural observation, not a claim that every Korean coffee drinker shares the preference.
For a satisfying version, consider the whole dilution sequence. Espresso contributes the coffee concentrate, while water and melting ice change strength as the drink sits. Compare recipes using the same cup and ice quantity before changing beans. A washed coffee can provide a relatively clear flavour reference, but individual lots and roast development matter more than a blanket rule about processing.
Taste the drink soon after mixing and again as the ice melts. If it becomes too weak, adjust the starting water or concentrate rather than simply choosing a darker roast. At a café, ask how the house prepares its iced Americano before assuming the recipe matches one you use at home.

The conversation
A good question can make a better brew.