Cold Brew, Steeped Slow

Cold brew replaces heat with time, and that single substitution decides everything else about it. Twelve to sixteen hours in cold water extracts the sugars and the chocolate and caramel notes almost completely while barely touching the fruit acids and the bitter compounds, because both of those need heat as well as duration to come out of the grounds.

What arrives is therefore sweeter and rounder than the same beans brewed hot, and noticeably flatter. Nothing was added to make it sweet; the acidity that would normally balance the sugars simply never made it into the water. That also makes it a poor way to taste an expensive single origin and an excellent way to make a large batch of pleasant coffee from something ordinary.

Most cold brew is made as a concentrate and diluted afterwards, which is the source of nearly every complaint that it is too strong. That also explains why cold brew and iced coffee are different drinks rather than two names for one: the second is brewed hot and chilled, and keeps the acidity the first never extracted.

Grind is the variable people get wrong first. Cold water extracts slowly, so the instinct is to grind finer and compensate, and that produces a cloudy, muddy concentrate that is difficult to filter and tastes of the fines rather than the coffee. Coarse and even is the answer, which makes the grinder the piece of equipment that decides the result.

Time is more forgiving than any other brewing variable on this site. Twelve hours and eighteen hours both give a drinkable concentrate, and the difference between them is strength rather than quality, so a batch forgotten overnight is not a batch ruined.

Keeping it is where the method pays off. A sealed concentrate holds in the fridge for a week or more with very little change, because the acids that would normally turn a brewed coffee stale were never extracted. That, rather than the taste, is the reason cold brew suits a household that drinks coffee through the week.