1. What a coffee ratio actually means

A brewing ratio compares dry coffee with the water you add, by weight. At 1:16, every gram of coffee gets 16 grams of water. So 20 g of coffee needs 320 g of water. This is the water going into the brewer, not the coffee coming out: the grounds hold some water back.

  • Find the water: coffee weight × ratio. At 1:15, 20 g × 15 = 300 g water.
  • Find the coffee: water weight ÷ ratio. At 1:16, 400 g ÷ 16 = 25 g coffee.
  • For everyday hot filter coffee, try 1:15 to 1:17 as a starting range. With 20 g coffee, that is 300–340 g water.
  • For the same coffee dose, less water usually makes a stronger cup; more water usually makes a lighter cup. Stronger does not automatically mean better extracted.

2. Use a scale, not a scoop

A scoop measures volume. Different beans and grind sizes pack differently, so equal scoops can weigh different amounts. A kitchen scale that reads grams is enough to begin; you do not need a complicated coffee setup.

  • Put your empty brewer or cup on the scale and press tare to reset it to zero.
  • Weigh the dry coffee. Tare again before adding water.
  • Add water until you reach the recipe’s weight. For everyday brewing, 1 g water is roughly 1 ml.
  • Write down the coffee, water, and grind setting. A repeatable cup gives you something useful to adjust.

3. Keep your water consistent

Start with fresh drinking water you enjoy. If your tap water smells of chlorine or tastes unpleasant, try freshly filtered drinking water. Keep the water source steady while testing ratios, so you can tell what changed. Minerals and temperature also affect brewing; a ratio alone cannot fix every flavor problem.

  • For this French press recipe, use water just off the boil and keep that routine consistent.
  • If you compare water sources, use the same beans, dose, grind, and brewing time.
  • For iced pour-over, count the weighed ice as part of the total water. For cold brew, follow its own recipe rather than assuming a hot-coffee ratio fits.

4. Separate strength from grind size

Ratio helps set strength. Grind size helps control how the coffee extracts. A weak but pleasant cup may need more coffee for the same water. A sharply sour, thin cup may need a slightly finer grind. A harsh, drying cup may need a slightly coarser grind. These are starting experiments, not rules that fit every bean.

  • Change one thing at a time. Keep the ratio steady while testing a grind adjustment.
  • If the flavor is balanced but the cup feels too light, try 1:15 instead of 1:16.
  • If it feels too heavy, try 1:17. Taste after the coffee cools a little before deciding.
  • Moka pots work to their own basket and chamber size. Follow the pot’s instructions rather than scaling this filter-coffee recipe.

5. Put it together: a French press recipe

Start with 30 g coffee and 500 g water, a ratio of about 1:16.7. Use a medium-coarse grind, a timer, and a press with room for the water and grounds. For a smaller batch, 15 g coffee and 250 g water keep the same ratio.

  1. Warm the empty press with hot water, then discard that water. Weigh in 30 g coffee.
  2. Tare the scale. Start the timer and add 500 g water just off the boil. Stir gently to wet all the grounds.
  3. Set the lid on with the plunger raised. Steep until the timer reaches 4 minutes.
  4. On a stable counter, press slowly. Stop if you meet strong resistance. Pour all the coffee into cups or a carafe.
  5. Taste and make a note. If it is balanced but weak, try 32 g coffee with the same 500 g water next time. If it is harsh and dry, keep 30 g and try a slightly coarser grind instead.
One useful thing

Save one recipe that tastes good. It is your starting point, not a test you have to pass.

Keep brewing