Choose a starting ratio by weight
For a first comparison brew, try 1:15: 1 gram of ground coffee for every 15 grams of water added. This is an editorial starting point, not a universal French press standard or a result from our own taste test. Use the same beans and method while you adjust it.
Coffee dose = water added ÷ ratio. At 1:15, 300 g of water needs 20 g of coffee; 600 g needs 40 g. A smaller denominator means more coffee for the same water. Measure water added, not the volume you expect to pour into your cup.
Recipes differ substantially. Blue Bottle’s published French press recipe uses 30 g of coffee and 350 g of water, a ratio of about 1:11.7, with a coarse grind and four-minute brew. If you follow that recipe, keep its dose and method together instead of mixing it with a different ratio chart.
Dose chart: water going into the press
Choose a water mass that leaves safe room for the grounds, filter and headspace specified by your press maker. The 1,000 g row is arithmetic for a sufficiently large press; it is not permission to put a litre of water plus grounds into a nominal one-litre vessel. Doses below are rounded to 0.1 g.
Water added | 1:12 coffee | 1:15 coffee | 1:17 coffee |
|---|---|---|---|
240 g | 20.0 g | 16.0 g | 14.1 g |
300 g | 25.0 g | 20.0 g | 17.6 g |
350 g | 29.2 g | 23.3 g | 20.6 g |
500 g | 41.7 g | 33.3 g | 29.4 g |
600 g | 50.0 g | 40.0 g | 35.3 g |
750 g | 62.5 g | 50.0 g | 44.1 g |
1000 g | 83.3 g | 66.7 g | 58.8 g |
Water added is not finished coffee
Some liquid remains with the grounds and in the vessel. The amount depends on the coffee, press and how you pour; a fixed retention estimate is not a guaranteed serving yield. Measure your own batch if the amount in the mug matters.
Worked example, using an explicit planning assumption: let retained liquid be 2 g per gram of dry coffee. With 240 g water and 16 g coffee, estimated drink = 240 − (2 × 16) = 208 g. The assumption can be wrong for your press; the arithmetic should still be consistent.
To plan a target beverage mass B at ratio R with assumed retention k, use coffee = B ÷ (R − k), then water = R × coffee. For B = 300 g, R = 15 and k = 2: coffee ≈ 23.1 g and water ≈ 346.2 g. This estimates 300 g poured out. Do not calculate a dose for 300 g water and then add extra water for retention: that changes the ratio.
For a better second batch, weigh the poured drink. Estimate k = (water added − drink poured) ÷ coffee dose, using the same pouring method. Treat it as a practical batch estimate: splashes, vessel residue and dissolved coffee also affect the measurement. Check the resulting water dose against the safe fill limit; brew twice if necessary.
Cups, tablespoons and press labels
A press labelled “eight cups” does not promise eight household mugs. Read its stated capacity and safe fill instructions, and measure the mug you actually use. A US fluid ounce is a volume unit; grams are mass. For kitchen planning, 1 ml of water is approximately 1 g, but that does not make every serving or scoop an exact conversion.
A tablespoon of grounds has no fixed mass: roast, grind, packing and the spoon change it. If you lack a scale, calibrate your own level spoon once with a borrowed scale. If that spoon weighs 5 g, four spoons provide about 20 g and pair with 300 g water at 1:15. The 5 g is an example, not a promise about your spoon.
Run one repeatable brew, then change one thing
Record your beans, water mass, coffee mass, grind setting, water temperature or kettle routine, and steep time. Use one complete recipe as your first method, the maker’s handling instructions, and a timer. Press gently; stop if resistance is excessive, and pour the finished coffee off the grounds.
If the result is simply too concentrated, test a little measured dilution in the cup before changing your next batch. If it is too dilute, compare a slightly larger coffee dose at the same water mass while keeping the rest of the method fixed. Taste is the result to compare; neither change guarantees that every flavor problem will disappear.
For harshness, sourness or sediment, do not diagnose from a single word alone. Record what happened and compare one change in grind or brew method against the original. Changing dose, grind and steep time at once makes the result hard to interpret. A ratio changes concentration and extraction conditions; it does not uniquely determine bitterness or acidity.
Copy this brew record
Date / beans: ____ | coffee: ____ g | water added: ____ g | ratio (water ÷ coffee): ____ | grind: ____ | water routine: ____ | steep time: ____ | drink poured: ____ g | taste: ____ | one change for next brew: ____
This record, the dose chart and the yield calculation let you size and repeat your own batch here. No external calculator or reference-site account is needed.
Recipe reference and calculation basis
The chart and yield examples are calculations, not measurements from a brewing experiment. The retention value is labelled as an assumption. The linked recipe is a separate published method; recipe details were checked on 28 October 2026.