The drip coffee ratio, minus the courtroom testimony

Begin with one useful number

Use one gram of coffee for every sixteen grams of water. That means about 30 grams of coffee for 480 grams of water. It is a starting point, not an oath sworn before the county clerk.

If it tastes thin

Use a little more coffee or grind slightly finer. Change one thing at a time. Coffee keeps poor records when several witnesses alter their stories at once.

If it tastes bitter or dry

Try a coarser grind or slightly less coffee. Keep the water just off the boil and give the bed an even soak.

The short version

Measure when it helps. Taste every time. The cup gets the final vote.