Bastien Brew Ratio
Brew ratio is the proportion of coffee grounds to water when brewing, typically 1:15 to 1:18 for filter coffee (1 g coffee to 15-18 g water) — the single most important variable for consistent, great-tasting coffee.
The brew ratio is the relationship between the amount of coffee grounds and water you use, expressed as coffee to water by weight. It is the single most important variable in coffee brewing, more impactful than grind size, water temperature, or pouring technique. Get the ratio right and you are most of the way to a great cup. Get it wrong and no amount of technique will save it.
I spent years eyeballing scoops before I finally bought a $15 scale. The first time I weighed 15 grams of coffee and 240 grams of water at exactly 1:16, the difference in consistency blew me away. Same beans, same grinder, but every cup tasted the way I wanted it to.
How do brew ratios work?
A brew ratio is expressed as coffee : water by weight in grams. A ratio of 1:16 means 1 gram of coffee for every 16 grams of water.
| Coffee dose | Ratio | Water needed | Approximate yield |
|---|---|---|---|
| 15 g | 1:16 | 240 g | 1 cup (220 ml) |
| 20 g | 1:16 | 320 g | 1 large mug (295 ml) |
| 30 g | 1:16 | 480 g | 2 cups (440 ml) |
| 42 g | 1:16 | 672 g | 4 cups (Chemex) |
| 60 g | 1:16 | 960 g | 1 liter batch |
The yield is slightly less than the water weight because coffee grounds absorb roughly twice their weight in water. A kitchen scale is essential here: volumetric scoops can vary by 20-30% depending on grind size and how you scoop.
What is the coffee-to-water ratio for each brew method?
| Method | Ratio range | Starting point | Flavor profile |
|---|---|---|---|
| Pour-over (V60, Kalita) | 1:15 to 1:17 | 1:16 | Clean, bright, nuanced |
| Chemex | 1:15 to 1:17 | 1:16 | Clean, sweet, lighter body |
| French press | 1:14 to 1:16 | 1:15 | Full body, rich, heavier |
| AeroPress | 1:12 to 1:16 | 1:15 | Versatile, adjust to taste |
| Drip / batch brewer | 1:15 to 1:17 | 1:16 | Consistent, crowd-friendly |
| Moka pot | 1:7 to 1:10 | 1:8 | Strong, concentrated |
| Cold brew concentrate | 1:4 to 1:8 | 1:5 | Very strong, dilute 1:1 before drinking |
| Cold brew ready-to-drink | 1:12 to 1:15 | 1:14 | Smooth, ready to drink |
| Espresso | 1:1.5 to 1:2.5 | 1:2 | Intense, thick, concentrated |
| Turkish / Cezve | 1:9 to 1:12 | 1:10 | Very strong, thick body |
These are starting points. Every coffee, roast level, and personal preference is different. The best coffee to water ratio is the one that tastes right to you.
How does brew ratio affect flavor?
Changing the ratio shifts the balance between strength (concentration) and extraction (how much flavor is pulled from the grounds):
| Ratio | Strength | Extraction | Typical taste |
|---|---|---|---|
| 1:12 – 1:14 | Strong | Higher | Bold, intense, sometimes bitter |
| 1:15 – 1:16 | Medium | Balanced | Sweet, clean, well-rounded |
| 1:17 – 1:18 | Light | Lower | Delicate, tea-like, sometimes thin |
| 1:19+ | Weak | Under-extracted | Sour, watery, lacking body |
A stronger ratio (more coffee, less water) does not automatically mean better. Very strong brews can taste bitter because more compounds are extracted. The SCA golden ratio of 1:16 to 1:18 hits the sweet spot for most people.
How do you find your ideal brew ratio?
Fine-tuning beyond ratio
Once your ratio is dialed in, you can adjust flavor through these secondary variables:
| Variable | Effect when increased | Effect when decreased |
|---|---|---|
| Grind size (finer) | More extraction, stronger | Less extraction, weaker |
| Water temperature | More extraction, brighter | Less extraction, sweeter |
| Brew time | More extraction, bolder | Less extraction, lighter |
| Agitation (stirring) | More even extraction | Less even extraction |
The key discipline is changing only one variable at a time. If you change ratio and grind size simultaneously, you will not know which change affected the taste.
Why weigh coffee instead of scooping?
| Method | Accuracy | Consistency | Best for |
|---|---|---|---|
| Kitchen scale (grams) | High (±1g) | Excellent | Anyone who wants repeatable results |
| Standard scoop (~10g) | Low (±3-5g) | Poor | Casual brewing where precision is not important |
| Tablespoon (~5-7g) | Very low (±3g) | Poor | Emergency only |
A standard coffee scoop holds roughly 10 grams, but this varies dramatically with grind size: coarse grounds weigh less per scoop than fine grounds. A kitchen scale that reads to 0.1 g or 1 g removes all guesswork and costs less than a bag of specialty coffee.
What is the brew ratio for espresso?
Espresso uses a fundamentally different ratio and deserves its own section:
| Espresso style | Dose | Yield | Ratio | Time |
|---|---|---|---|---|
| Ristretto | 18 g | 27 g | 1:1.5 | 22-27 s |
| Normale | 18 g | 36 g | 1:2 | 25-30 s |
| Lungo | 18 g | 54 g | 1:3 | 30-40 s |
For espresso, the ratio is dose (dry coffee in the portafilter) to yield (liquid in the cup). A 1:2 ratio is the modern standard: 18 g in, 36 g out. Ristretto pulls less water for a sweeter, more concentrated shot. Lungo pulls more for a lighter, more diluted shot.
What is the brew ratio for cold brew?
Cold brew uses a much stronger ratio because cold water extracts less efficiently than hot water, the concentrate is typically diluted before drinking, and long brew times (12-24 hours) compensate for lower temperature.
| Style | Ratio | Steep time | How to serve |
|---|---|---|---|
| Concentrate | 1:5 | 12-18 hours | Dilute 1:1 with water, ice, or milk |
| Ready-to-drink | 1:14 | 18-24 hours | Drink straight over ice |
| Japanese iced (flash brew) | 1:16 | 2-4 minutes | Brew hot over ice, no dilution needed |
How do you scale a brew ratio?
Scaling a brew ratio is straightforward multiplication. If your single cup uses 15 g coffee at 1:16, scaling to four cups is 60 g coffee and 960 g water. The ratio stays the same; only the absolute amounts change.
One thing to watch: extraction efficiency can change at different batch sizes. A 1-liter batch in a Chemex may extract slightly differently than a single cup. Adjust grind size if the larger batch tastes different than the small one.
What are the most common brew ratio mistakes?
What are the best brew ratio tips?
- Write down your ratio when you brew a cup you love. You will forget otherwise.
- Different roast levels often taste best at different ratios: lighter roasts shine at 1:16, darker roasts at 1:15
- Water quality matters almost as much as ratio. Filtered water with some mineral content brews best. I switched from tap water to filtered water with a pinch of baking soda and the improvement surprised me more than any ratio change.
- Pre-wet your filter (pour-over) to avoid paper taste, but do not count that water in your ratio
- When sharing coffee recipes with others, always include the ratio. It is the most transferable piece of information
Brew ratios in Fond
Fond's Coffee Lab has a coffee ratio calculator built in. Pick your brew method, enter your dose, and it calculates exactly how much water to use. The brew log tracks each cup (dose, ratio, grind, temperature, and your tasting notes) so you can reproduce your best brews and refine the ones that were not quite right. Over time, the Coffee Lab builds a profile of what ratios work best for each bean and method combination.
