These two words are used interchangeably in conversation and mean quite different things, and confusing them is why dialling in feels random.
Extraction
What proportion of the coffee grounds dissolved. Measured as extraction yield, 18 to 22% is the good range.
Controlled by grind size, temperature, contact time and agitation.
Determines whether the coffee tastes sour, balanced or bitter.
Strength
How much dissolved coffee is in the finished drink. Measured as TDS — total dissolved solids — around 1.15 to 1.45% for filter, 8 to 12% for espresso.
Controlled by the brew ratio.
Determines whether the coffee tastes weak or intense.
Why the distinction matters
A coffee can be:
- Weak and under-extracted — dilute and sour. Grind finer and use more coffee.
- Weak and well-extracted — dilute but balanced. Just use more coffee.
- Strong and over-extracted — intense and bitter. Grind coarser.
- Strong and well-extracted — intense and good. This is espresso.
If you treat “weak” as one problem, you will change the wrong variable half the time.
The practical method
Ask two questions of every cup. Is it sour or bitter? — that is extraction. Is it thin or intense? — that is strength.
Fix extraction first with grind, then strength with ratio. In that order.
Last reviewed 8 August 2026