Every café has one thing most home kitchens do not: a set of scales. Baristas weigh every dose. Not because they are obsessive, but because weight is the only thing that actually tells you what is in the cup. A tablespoon of coarsely ground coffee weighs less than a tablespoon of fine-ground coffee. Scoops lie. Scales do not.
The ratio that connects your dose to your water is the single most controllable variable in home brewing. Here is how it works, why it matters, and what numbers to use for every method worth knowing.
The ratio explained
Coffee-to-water ratio is expressed as a number like 1:15 or 1:17. Read it as: one gram of coffee for every fifteen (or seventeen) grams of water. It is a weight ratio, not a volume ratio — grams on both sides.
The range you will see in specialty coffee circles runs from roughly 1:12 (strong, concentrated) to 1:18 (lighter, more delicate). Most everyday brew guides land between 1:15 and 1:16. Espresso is different entirely — it uses a brew ratio (dose in / yield out) that runs around 1:2 or 1:2.5.
You do not need to memorise ratios. You need to find the one your palate likes and repeat it consistently. A scale makes that possible.
Why the ratio matters more than you think
When the ratio is off, the flavour cannot fully compensate. Under-dosed coffee tastes thin and watery regardless of how good the roast is. Over-dosed coffee tastes muddy and bitter regardless of how precise your grind is. The ratio sets the ceiling. Everything else — grind, temperature, technique — works within it.
This is why "just add more coffee" is not always the fix for a weak cup. If your grind is too coarse and you add more coffee, you get more of an under-extracted brew, not a stronger one. Fix the ratio and the grind together, and the cup sorts itself out.
Ratios by brew method
Each method has a different contact time and extraction dynamic, which shifts the ideal starting ratio.
Pour-over and filter (V60, Chemex, filter machine)
Starting ratio: 1:16
Pour-over is a precision method. The ratio of 1:16 gives you a clean, balanced cup with clarity in the flavour. Want more body and strength? Pull it to 1:15. Want something lighter and more delicate? Push to 1:17.
For a standard 300ml mug: 19g coffee. For a larger 400ml cup: 25g coffee. The filter machine in your kitchen works on the same principle — check the water volume in the carafe and dose accordingly.
Cafetiere (French press)
Starting ratio: 1:15
The cafetiere extracts a little more aggressively than pour-over due to full immersion and the lack of a paper filter. A slightly tighter ratio at 1:15 produces the body and depth that suits the method. Going to 1:14 gives you a stronger, almost espresso-adjacent cup. Going to 1:17 in a cafetiere tends to produce something flat and watery — the method needs the dose.
Standard two-cup cafetiere (350ml): 23g coffee. Four-cup (500ml): 33g coffee. Eight-cup (1 litre): 67g coffee.
AeroPress
Starting ratio: 1:13 to 1:15, depending on method
The AeroPress is the most flexible brewer you can own. For a concentrated, espresso-adjacent result: 18g of coffee to 50ml of water, pressed in 30–40 seconds. For a full cup: 15g to 200ml, steeped for 1–2 minutes. Both work. The AeroPress forgives imprecision more readily than most methods, which makes it a good place to experiment with ratios.
Espresso
Brew ratio: 1:2 to 1:2.5 (dose in / yield out)
Espresso uses a different ratio concept. You measure the dry dose going into the portafilter and the liquid yield coming out. A common starting point: 18g in, 36g out, in 27–30 seconds. This 1:2 ratio produces a balanced, full espresso shot with sweetness and body.
Longer ratios (1:2.5 or more) produce a lighter, more acidic "lungo" style. Shorter ratios (1:1.5 or less) produce a ristretto — intensely concentrated, syrupy, with very low bitterness.
High Noon Espresso is developed for this method. Start at 18g in, 36g out, and adjust from there.
Cold brew
Starting ratio: 1:8 (concentrate) or 1:12 (ready to drink)
Cold brew uses a much heavier ratio because cold water extracts far less efficiently than hot. A 1:8 ratio steeped for 18 hours in the fridge gives you a concentrate you dilute 1:1 with water or milk when serving. A 1:12 ratio produces something closer to ready-to-drink strength after the same steep time.
Cold brew is forgiving at the edges — ratios between 1:7 and 1:10 for concentrate all produce acceptable results. Taste it before diluting and adjust the dilution ratio to your preference.
Quick reference: doses for common cup sizes
These use a 1:15 ratio as the base — adjust slightly based on method guidance above.
- Small mug (200ml): 13g coffee
- Standard mug (250ml): 17g coffee
- Large mug (350ml): 23g coffee
- Travel cup (400ml): 27g coffee
- Cafetiere, 2-cup (350ml): 23g coffee (1:15)
- Cafetiere, 4-cup (500ml): 33g coffee (1:15)
- Cafetiere, 8-cup (1 litre): 67g coffee (1:15)
How to use a scale without slowing down your morning
The friction is real. Getting the scale out, zeroing it, weighing — it adds steps to a routine that most people want to finish quickly. Here is how to make it habit:
- Leave the scale on the counter next to the kettle. Out of sight means out of routine.
- Weigh your coffee into a dedicated scoop or cup the first week. You will quickly learn what your target dose looks like by eye — then the scale becomes a check rather than a requirement.
- If you use a cafetiere or pour-over jug, tare the scale with it on top and pour water directly onto it. One weigh step instead of two.
For automatic calculations based on your setup, use the coffee brewing calculator to get exact doses for your cup size and method. Input the numbers once, and it does the ratio maths so you do not have to.
The ratio is the foundation
Dialling in the ratio is the first thing to fix before worrying about grind, water temperature, or technique. It costs nothing and the difference in the cup is immediate. Start at 1:15 for most methods, taste it honestly, and adjust one step at a time until the cup is what you want it to be.
Good coffee repays the attention. Browse the Western Tamp range and find the roast worth brewing properly. The ratio is yours to dial in from there.