Batch Brew Calculator

Batch brew is what most cafés run all day: a commercial drip brewer filling carafes or airpots at volume. Getting the dose right is simple math that most operators eyeball, which is why so much batch coffee tastes off. If your café is using a scoop and “it looks about right,” use a scale instead. This calculator will show you exactly where you land.

The SCA Batch Brew Standard window is 1:15 to 1:20 (50–67 g/L). The midpoint of that window is about 1:16.67 (60 g/L). Most cafés operate at 1:16 to 1:17, which sits comfortably inside the window. Use the ratio that produces the cup you want, not whichever number sounds official.

Serving math is often wrong because people conflate brew volume with drinkable volume. Coffee grounds absorb roughly twice their dry weight in water during brewing. A 1-liter batch with 62.5 g of coffee leaves about 875 mL in the carafe, not 1000 mL. Add a small evaporation allowance during hot-hold service and plan accordingly.

Water quality matters for batch brew just as it does for any other method. The SCA Water Quality Handbook recommends 75–250 mg/L TDS for brew water. If your water falls outside that range, install a filtration system on the brewer or use properly filtered water when scaling up. Dose adjustments alone will not fix taste problems caused by mineral content.

When scaling up, keep the ratio constant and multiply dose and water proportionally. Measure coffee by weight, not by scoop. A 10-liter urn at 1:16 needs 625 g of coffee; a scoop estimate can put you 20% off in either direction.

Grind size: the ratio stays the same as batch size grows, but for very large batches grind slightly coarser than your standard setting. Large brew volumes extract more aggressively; a coarser grind compensates and avoids over-extraction.