THE BREW BENCH / BREW
Cold brew. No dilution guesswork.
Plan a batch or dilute concentrate you already have, with measured yield, your chosen ratio and melted-ice accounting.
Two ratios, two different jobs
A brew ratio of 1:5 means 100 g dry grounds with 500 g water. A dilution ratio of 1:2 means one part already-brewed concentrate plus two parts water or milk. These are different measurements: a 1:5 brew does not tell you an exact caffeine dose or measured dissolved-solids strength.
For 200 ml measured concentrate at 1:2, add 400 ml liquid to make 600 ml before any extra serving ice. If 100 g of that addition will be melted ice, add 300 ml liquid and count the 100 g ice within the allowance. For a 300 ml finished serving at 1:2, start with 100 ml concentrate.
Keep the batch cold. Use clean equipment, refrigerate during steeping and storage at 4°C / 40°F or below, label the batch, and use promptly. This tool does not establish a safe shelf life. Milk additions follow their package guidance. See the complete cold-brew guide and food-safety sources.