Get it roughly right and everything else becomes adjustable. Get it wrong and no amount of technique will save the cup.
Brew ratio calculator
The ratios we use at the bar. Pick a method; we will do the arithmetic.
Method15g coffee · 240g water
Ratio 1:16
Ratios from the bar at Prodigal Roasters
What is a brew ratio?
A brew ratio is the amount of coffee you use relative to the amount of water, written as 1:15, 1:16, 1:17, and so on.
The first number is always the coffee. The second is always the water. At 1:16, every gram of ground coffee meets sixteen grams of water: 15 g of coffee, 240 g of water, one honest mug.
Two small things make ratios work.
Measure by weight, not by scoop: Beans vary in density, so a scoop of one coffee is not a scoop of another. A basic scale removes the guesswork. And because one millilitre of water weighs one gram, you can weigh the water too. No measuring jug required.
Filter and espresso ratios are different: This is the part most guides hurry past, and it causes no end of confusion. For filter coffee, the ratio describes what goes in: dry coffee to water for brewing. For espresso, it describes what comes out: dry coffee to liquid in the cup. An 18 g dose pulled to 36 g of espresso is a 1:2 shot, even though far more water than that passed through the machine. The puck keeps some for itself.
Same notation. Different meaning.
One more thing before the numbers: A recipe tells you how to brew one cup, but a ratio tells you how to brew any cup: for two people, a full carafe, or the 300 ml mug you actually own.
Starting coffee brew ratios, by method
These are doors, not destinations. Walk through, then adjust to taste.
| Method | Ratio | In practice |
|---|---|---|
| Espresso—our house style | 1:1 | 18 g in → 18 g out, ~32 seconds |
| Espresso—the common standard | 1:2 | 18 g in → 36 g out, 25–32 seconds |
| Lungo | 1:3 | 18 g in → 54 g out |
| Pour-over (V60, Solo Dripper) | 1:15–1:17 | 15 g → 240 g water |
| French press | 1:15 | 30 g → 450 g water |
| Iced/flash brew | ~1:15 overall | 20 g → 200 g hot water over 100 g ice |
| Cold brew (concentrate) | 1:5–1:8 | 100 g → 600 g water, then dilute to taste |
You may have heard of the "golden ratio". The Specialty Coffee Association's golden cup standard sits around 1:18, a well-researched reference point for balanced filter coffee, and a perfectly good place to begin. We tend to brew a touch tighter, between 1:15 and 1:17, because we like a little more presence in the cup. Neither of us is wrong. That is rather the point.
Why we pull our espresso at 1:1
Walk into most good cafés and the espresso will be a 1:2. Eighteen grams in, thirty-six grams out. It is the modern standard for a reason: balanced, clear, forgiving.
We go shorter.
Our house shot on Reckless Blend is a 1:1 ristretto, 18 g of coffee in, 18 g of liquid out, in roughly 32 seconds. Half the drink. None of the compromise. The result is dense and syrupy, with the kind of sweetness that does not need explaining.
A shorter ratio is less forgiving, though. There is nowhere for a mistake to hide in eighteen grams. So we dial it in the same way every time. We call it the three-shot journey.
Shot one, too slow. The grind is too fine. The shot drags past forty seconds and turns bitter and hollow.
Shot two, too fast. We overcorrect coarser. It gushes through in twenty-two seconds, thin and sharp.
Shot three, the middle. A small step back towards fine. Thirty-two seconds. There it is.
Two habits make this work. Change one variable at a time, or you will never know which change did what. And move macro before micro: ratio and grind set the shape of the shot; temperature and half-gram dose adjustments are the fine-tuning at the end.
If your shots keep landing sour, do not reach for the ratio first. Reach for the grinder.
The ratio should change as your coffee rests
Here is something the ratio charts will not tell you: the right number moves.
Freshly roasted coffee is full of carbon dioxide. For the first couple of weeks off roast, that gas pushes back against the water, and extraction becomes a small negotiation. So when a coffee is fresh, we brew it generously, a wider ratio, hotter water, a longer bloom, to help the water win.
When Aki Geisha is a week off roast, we brew it at 1:17 with water just off the boil, bloom it for a full minute, and let the brew run about four minutes. We take everything the coffee will give.
By week three or four, the coffee has settled. The gas has gone quiet, and it gives itself up far more easily. The same recipe that sang in week one now tips into bitterness. So we ease off everything: a slightly tighter ratio, cooler water, a coarser grind, a shorter brew.
The coffee changes. The ratio should keep it company.
If a bag that tasted wonderful a fortnight ago has gone flat or harsh on you, this is usually why.
Our house brew recipes
Three recipes we pour every week at the roastery. Steal them.
Filter, fresh coffee (our Aki Geisha method)
- Ratio: 1:17 (15 g coffee, 255 g water)
- Water: 97°C, just off the boil
- Grind: a step finer than your usual filter setting
- Bloom: 60 seconds
- Total time: about 4 minutes
Built for coffee inside its first two weeks. As the bag rests, walk each setting gently backwards.
Pour-over, everyday (the Solo Dripper)
- Ratio: 1:16 (15 g coffee, 240 g water)
- Water: 93°C
- Bloom: 30 seconds
- Pours: steady spirals to weight
- Total time: 2:30–3:00
The Solo's fast flow rewards a slightly finer grind than a V60. If the brew finishes under two and a half minutes, tighten the grind rather than the ratio. It is the same dripper behind the 2025 Singapore Brewers Cup win.
Iced, flash-brewed
- Ratio: ~1:15 overall (20 g coffee, 100 g ice, 200 g hot water)
- Method: ice goes in the server; brew hot and concentrated straight onto it
The trick to iced coffee is remembering that the ice is water. Count it inside your ratio, brew strong over the top, and the melt lands you exactly where you meant to be, chilled instantly, aromatics intact, no dilution tax.
When the ratio is not the problem
The ratio decides how strong a coffee can be. It does not decide how good it will taste.
Extraction does, and extraction is steered by five dials working together: grind size, water temperature, time, ratio, and agitation. When a cup goes wrong, the ratio is usually the last dial to blame.
Read the cup first.
Sour, thin, unfinished → under-extracted. The water left too early. Grind finer, brew hotter, give it longer.
Bitter, dry, heavy → over-extracted. The water overstayed. Grind coarser, brew cooler, cut it shorter.
Then move one dial, taste, and move again. Instead of asking what is wrong with the coffee, ask what is missing from the cup. The answer is nearly always in that list of five, and it is nearly always fixable by tomorrow morning.
If you would rather troubleshoot side by side with us, we run private brewing workshops at the studio.
How to improve your workflow
The difference between a lucky cup and a repeatable one is workflow, a handful of small habits, none of them glamorous.
Brew to weights, everywhere: Scale under the brewer. Scale under the espresso cup. The moment you stop guessing, every adjustment starts to mean something.
Dial in like it is a conversation: Our bar ritual is the three-shot journey: the first shot runs slow and bitter, the second overcorrects fast and sharp, the third lands in the middle. Two informed moves beat ten hopeful ones.
Track the roast date: This is the habit the charts never mention: the right recipe moves as coffee rests. Fresh coffee is full of carbon dioxide that pushes back against the water, so in the first two weeks we brew generously: wider ratio, hotter water, longer bloom. Our Aki Geisha gets 1:17 at 97°C with a full-minute bloom when it is a week off roast. By week three the gas has gone quiet and the same recipe tips into bitterness, so we ease everything off, tighter ratio, cooler water, coarser grind, shorter brew. The coffee changes. The recipe should keep it company.
Keep a five-second log: Coffee, roast date, ratio, grind setting, time, one honest word about the taste. A week of notes will teach you more than a month of forum threads.
Recalibrate on every change. New bag, new grinder, new water, treat each as day one, and let the ratio be the thing you trust while everything else settles.
Questions we hear at the bar
What is a good coffee-to-water ratio for beginners?
Start filter coffee at 1:16, 15 g of coffee to 240 g of water. It is balanced, forgiving, and easy to scale. Go tighter for more body, wider for more clarity.
What does a 1:2 ratio mean in espresso?
Dose to yield: 18 g of ground coffee pulled to 36 g of liquid espresso in the cup. Espresso ratios describe what comes out, not the water that went in.
How much coffee per cup?
For a standard 240 ml mug at 1:16, about 15g, roughly three level tablespoons. Density varies between coffees, though, which is why we will always gently push you towards a scale.
Does the ratio change for iced coffee?
The overall ratio stays familiar (~1:15), but 30–40% of your water becomes ice in the server. Brew hot and concentrated over it; the melt completes the maths.
Is a 1:1 espresso too strong?
It is stronger, certainly dense, syrupy, intense. Too strong is a matter of taste. It is also less forgiving to dial in, so expect to spend a shot or two finding the sweet spot.
What ratio should I use for cold brew?
Steep a concentrate between 1:5 and 1:8 for 12–18 hours, then dilute roughly 1:1 with water or milk. Cold extraction is slow, so it borrows its strength from a heavier dose.
Start at 1:16. Taste. The number will teach you the rest.
A page can only take you so far; at some point coffee is a thing you do with your hands, ideally with someone nearby who has made every mistake already.
Bring us the cup that confused you, the roastery at Mactaggart Road exists for exactly that conversation. If you would rather learn by doing, we run small brewing workshops at our studio, scales and spare shots included. Or, even better, we have a barista course.
However you brew: start somewhere honest, change one thing at a time, and trust your own tongue over anyone's chart. Including ours.