A bad cup is usually a matter of extraction, strength, or both. Across moka pot, French press, AeroPress, South Indian filter, and pour-over, you can adjust five basic variables:
| Variable | What it changes |
|---|
| Grind size | How easily water extracts the coffee |
| Water temperature | How quickly extraction happens |
| Coffee-to-water ratio | How strong the cup is |
| Contact time | How long extraction continues |
| Agitation | How much the coffee is disturbed during brewing |
Taste → Try this
| If your coffee tastes… | Try… |
|---|
| Sour or sharp | Grind finer |
| Thin | Use more coffee |
| Bitter or harsh | Grind coarser |
| Dry or astringent | Reduce agitation |
| Weak or watery | Use more coffee |
| Too strong | Use more water |
| Sour and strong | Grind finer |
| Bitter and weak | Grind coarser |
| Make one small change, taste the difference, and keep adjusting until the cup feels right. | |