Concentrates, dilution, and milk

Every cold drink you will ever build is one piece of arithmetic: how strong is the coffee, and what will dilute it before it is finished? A 1:5 concentrate cut one-to-one with water lands near a 1:10 — close to a bold filter coffee. Pour the same concentrate straight over a full glass of ice and the ice does the cutting for you: expect 20 to 25 percent meltwater by the time the glass is empty, and more on a hot day.

This is why drinks built for ice should start noticeably stronger than tastes right at first sip. Brew for the last sip, not the first.