Is the coffee too bitter?
A bitter taste is most often the result of over-extraction – the water has extracted too much from the coffee, including unpleasant, heavy notes.
What does that mean?
The coffee is over-extracted.
grinding is too fine
the brewing time is too long
Is your coffee too strong? Do this:
grind the coffee coarser
shorten the brewing time
lower the water temperature
use less coffee
If coffee tastes like something other than just bitter
Common mistakes
too fine grinding
too long brewing time
water temperature too high