Why your pour over coffee is bitter or sour, and how to fix it
Sour pour over coffee is under-extracted; bitter, drying coffee is over-extracted. If it is sour, grind finer, use hotter water or slow your pours. If it is bitter, grind coarser, use slightly cooler water or pour faster. Change one thing at a time and write down what you did.
Taste, cause and fix
Start with the first fix in each row and move right only if it is not enough.
| Taste | Cause | Change next time |
|---|---|---|
| Sour, salty, short finish | Under-extracted | Grind one step finer → water 2–3 °C hotter → pour more slowly |
| Bitter, astringent, drying | Over-extracted | Grind one step coarser → water 2–3 °C cooler → pour faster |
| Weak, watery | Too much water for the coffee | Lower the ratio (1:16 → 1:15) |
| Too strong, heavy | Too little water for the coffee | Raise the ratio (1:15 → 1:16) |
Change one variable at a time
If you change grind, temperature and ratio together, you will not know which one helped. Grind has the biggest effect, so adjust it first, then water temperature, then ratio. Write down the grams, ratio, grind setting, temperature and total time for each brew and you will usually dial it in within two or three cups.
Use brew time as a check
A V60 with 15–20 g of coffee usually finishes draining in 2:30 to 3:30. Much faster usually means the grind is too coarse and the cup tastes sour; past 4 minutes the grind is often too fine and the cup turns bitter. Comparing times only works if you brew the same recipe with the same timer each time.
Check how fresh your beans are
Beans roasted only a few days ago are full of gas, bloom hard and can extract unevenly. Old beans lose aroma and taste flat and bitter. One to four weeks after roasting is commonly considered the sweet spot, so check the roast date on the bag.
In Bloomcup
When a brew finishes, Bloomcup asks you to rate it with two sliders, sour to bitter and weak to strong, plus stars, and then shows a tip for next time, such as grinding a little coarser or using slightly cooler water. Ratings and notes stay in your brew log, where one tap brews the same recipe again. Add a roast date to your beans and Bloomcup shows how many days since roasting and when they taste their best.
FAQ
- Why is my pour over coffee sour?
- It is under-extracted. Grind one step finer or raise the water temperature by 2–3 °C.
- Why is my pour over coffee so bitter?
- It is over-extracted. Grind one step coarser, use slightly cooler water and avoid dragging out the pours.
- My coffee tastes weak. How do I make it stronger?
- Lower the ratio number. Going from 1:16 to 1:15 puts more coffee in the same water.
- Is there an app to take notes and rate your brew?
- Bloomcup logs sour to bitter, weak to strong, stars and notes for every brew for free, and suggests what to change next time.
Rate your cup and get a tip for the next one
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