Every brewer arrives with its own recipe, and the recipes disagree with each other in ways that suggest each method is its own discipline. They mostly are not. Underneath the different numbers is one ratio, expressed four different ways.
Roughly 60 grams of coffee per litre of water covers nearly every filter method you own. Press, cone, flat-bottom, cloth, siphon, electric drip. Learn one number, apply it everywhere, and let grind and contact time do the differentiating.
What to do
Weigh the water as well as the coffee. Water is the easier of the two to get wrong, because a "cup" is a different volume in three countries and no jug is accurate. One millilitre of water weighs one gram, so a kitchen scale reads both.
Then scale the ratio to whatever you are making:
| You are brewing | Water | Coffee |
|---|---|---|
| One mug | 250 g | 15 g |
| Two mugs | 500 g | 30 g |
| A full press | 1,000 g | 60 g |
That is the same ratio three times. Moldvaer's own method tables land on exactly these figures across a press, a cloth brewer, a siphon and a pour-over, which is what makes the spine visible once you write them side by side.
Three deliberate exceptions are worth knowing, because each has a reason:
- Cold drip runs about double, near 120 g per litre. It is a concentrate meant to be diluted or poured over ice, not a cup.
- Vietnamese phin runs about 70 g per litre. It is built to be cut with condensed milk.
- Moka runs nearer 50 g per litre. Steam pressure does extra extraction work, so it needs less coffee to reach the same intensity.
Why it works
A brew ratio is not a rule about correctness. It sets concentration: how much dissolved coffee ends up in each mouthful. Extraction, meaning what fraction of the grounds dissolved, is governed by grind and time instead. Holding the ratio steady across your shelf means the only things changing between brewers are the ones that are supposed to change.
This is why the number survives being applied to wildly different equipment. A press and a cone produce very different cups at 60 g per litre, and the difference comes from immersion versus percolation and from what the filter passes, not from the dose.
Treat 60 as the centre rather than the answer. Racineux and Tran give a working band of 55 to 80 grams per litre, with 55 reading mild and 80 reading strong. The band is the honest version: ratio is a taste dial you are allowed to move. Sixty is simply the place most people find comfortable, and the place to return to when a new brewer confuses you.
Do not use ratio to fix a sour or bitter cup. That is an extraction problem and ratio is the wrong tool for it. Set the balance with grind, then set the strength with this number.
How you know it worked
Brew the same coffee in two different brewers at the same ratio on the same morning. If both cups land in a similar place for strength while differing in texture and clarity, the spine is doing its job and you have isolated the brewer's real contribution.
The other test is simpler. When you buy an unfamiliar brewer, you should not need its recipe. Weigh the water, take 6 percent of it in coffee, grind to whatever the contact time suggests, and you will be close enough to start adjusting from. If that works, the number has been learned.
What this will not do
It will not apply to espresso. Espresso runs an entirely different ratio, around 1 part coffee to 2 or 2.5 parts liquid out, and it is roughly ten times the concentration of filter coffee. Nothing on this page transfers.
It will not make weak coffee taste strong. If your cup is thin at 60, go to 70 and see. The band exists precisely because tastes differ, and there is no prize for staying at the centre.
It will not correct for a brewer that runs long. An electric machine with a slow shower head or a press left standing after plunging will keep extracting past where you intended, and a correct ratio will not stop it.
And it will not survive a scoop. The number is denominated in mass. Measured by volume it drifts with grind size and roast level, which is the whole case against the scoop.
The one line to remember
Six grams of coffee for every hundred grams of water.
That is 60 g per litre expressed in the form you will actually use at the counter, and it is the last coffee ratio most people need to learn.
