Definition
Brew ratio is the relationship between the mass of coffee grounds and the mass of water used to brew. It directly controls the strength (TDS) of your final beverage.
More water relative to coffee = weaker, lighter-bodied cup. Less water = stronger, more concentrated cup. Ratio is independent of extraction percentage.
Key Insight
Brew ratio controls strength. Grind size controls extraction. These are independent variables.
Ratio Formats
Ratios are expressed in multiple formats. They all describe the same relationship:
Common Formats:
1:15 ratio
1 part coffee to 15 parts water. Example: 20g coffee + 300g water
60g/L
60 grams of coffee per liter of water. Equivalent to 1:16.67 ratio
Percentage (6.25%)
Coffee as percentage of total weight. 6.25% = 1:15 ratio
Most specialty coffee uses the 1:X format because it is intuitive and scales easily. A 1:15 ratio works the same whether you are brewing 20g or 200g.
Common Ratios and What They Produce
1:13 - 1:14 (Strong)
TDS: ~1.50-1.60%
Very concentrated. Intense flavor. Common for small batches or when you want maximum impact. Can feel heavy if over-extracted.
1:15 - 1:16 (Balanced)
TDS: ~1.30-1.45%
The most common pour-over ratio. Balanced strength and clarity. Good starting point for dialing in new coffees. Works for most roast levels.
1:17 - 1:18 (Light)
TDS: ~1.15-1.25%
Lighter body, higher clarity. Good for delicate coffees where you want transparency over intensity. Can taste watery if extraction is low.
These ranges assume well-extracted coffee (18-22% extraction). If extraction is low, even a strong ratio will taste weak because you have not dissolved enough material.
Making Adjustments
Adjusting ratio is simple: use more or less water while keeping coffee dose constant. Or use more or less coffee while keeping water constant.
When to Adjust Ratio:
- •Coffee tastes weak but balanced: Reduce water (stronger ratio like 1:14). Extraction is good, you just need more concentration.
- •Coffee tastes too strong/intense: Add more water (lighter ratio like 1:17). This will not fix extraction problems, only intensity.
- •Coffee tastes both sour and weak: Do not add more coffee. Grind finer instead. You have low extraction and low strength. Adding coffee makes it strong but still sour.
Pro tip: Once you find an ideal ratio for a coffee, stick with it and adjust other variables (grind, temperature) for flavor. Constantly changing ratio makes it harder to build consistency.