Cold Brew — brewing guide

Cold brew runs on a simple trade: temperature for time. Extraction rate falls steeply as water cools — meaningfully slower for every ten degrees you drop — so what hot water does in minutes, cold water needs half a day to approximate. But the trade is not symmetric. Some compounds, including many of the acids and volatile aromatics that give hot coffee its brightness and perfume, barely extract at low temperature no matter how long you wait. The result is structural, not incidental: a smooth, low-acid, chocolate-and-caramel cup that stays gentle because the sharp notes never left the grounds.

Grind coarse. Over a 12-to-24-hour steep even coarse particles extract fully, and a coarse bed is vastly easier to filter — fine grinds turn the strain into sludge and push extraction into woody, dusty territory. Steep at room temperature for a faster brew (12–16 hours) or refrigerated for a slower, slightly cleaner one (18–24 hours), then filter through paper or fine mesh.

Concentration is a choice you make at the ratio stage. Brew around 1:5 to 1:8 for a concentrate to cut with water, milk, or tonic; brew 1:12 to 1:15 to drink straight. Kept cold and sealed, it holds for a week or more — time is this method's ingredient at every stage.