The V60 is brilliant because it’s simple. It’s also maddening because it’s sensitive. Small changes in grind, pouring, and water can swing your cup from sharp and thin to heavy and harsh.
If you’re stuck in a cycle of “today it’s sour, tomorrow it’s bitter, and I’m not sure what I did”, you don’t need a new recipe. You need a diagnosis.
This guide is a practical, UK-kitchen-friendly way to troubleshoot pour-over coffee (V60, but it translates to most cone drippers). It’s built around a simple rule:
Change one thing at a time, and change it in the direction the cup is asking for.
Step 1: Name the problem (and don’t confuse it with something else)
People often say “sour” when they mean “acidic”, and “bitter” when they mean “strong”. Let’s separate a few common sensations.
Sour (unpleasant)
- Sharp, prickly, “green” acidity
- The flavour hits the sides of your tongue and feels unfinished
- Often paired with a watery body
Bitter (unpleasant)
- Drying, harsh finish (like over-steeped tea)
- The cup lingers in a way that feels heavy or burnt
- Can also feel a bit astringent (mouth-drying)
Weak / hollow
- The cup tastes thin and not particularly bright
- You can tell it’s coffee, but it’s missing sweetness and structure
Flat / dull
- No spark, no sweetness, no clarity
- Often points to water quality, stale ground coffee, or a recipe that’s under-agitated
Keep the description simple. Pick the dominant issue.
Step 2: Lock a baseline (so your changes mean something)
If everything changes every brew, you can’t learn anything.
For the next 3–5 brews, keep these fixed:
- Dose: 15g coffee
- Water: 250g
- Temperature: 94°C (or just-off-boil, wait ~45–60 seconds)
- Filter rinse: yes (hot water)
- Brew time target: roughly 2:45–3:30 (don’t worship this, just note it)
Pick one coffee and stick with it for troubleshooting. Different coffees naturally behave differently; you want to reduce variables.
Step 3: Use the “levers” in the right order
There are lots of things you can change. There are only a few that reliably move the cup in predictable ways.
Here’s a sensible order for home brewers:
- Grind size (biggest lever)
- Pouring/agitation (second biggest)
- Water temperature
- Ratio (only after the above)
- Brew time as a clue, not a target
Lever 1: Grind size (most of the time, it’s this)
Grind sets the surface area the water can work with.
- Too coarse → water doesn’t pull enough out → sour/weak
- Too fine → water pulls too much (and can choke flow) → bitter/astringent
If your cup is sour or weak: grind finer.
If your cup is bitter and drying: grind coarser.
How much? More than you think, but not a leap into the unknown. On most grinders, go one “notch” or a small step, then repeat the same brew.
A useful clue: if your drawdown is very fast (say, under ~2:30 for 250g), and the cup is sharp or thin, you’re likely too coarse. If it’s very slow (well over ~4:00) and the cup is harsh, you’re likely too fine and/or over-agitating.
Lever 2: Pouring and agitation (the stealth variable)
Agitation increases extraction. It also changes how fines settle in the filter, which changes flow.
Common mistakes:
- Pouring too aggressively, stirring like you’re making gravy
- Pouring from too high (extra turbulence)
- Over-swirling at the end, creating a muddy filter bed
If your cup is bitter/drying but your grind isn’t crazy fine: reduce agitation.
- Pour a little lower and gentler
- Fewer “rescue swirls”
- Aim for a calm bed and a consistent stream
If your cup is weak/hollow even when you’ve gone slightly finer: add controlled agitation.
- Slightly more energetic pours during the main phase
- One gentle swirl right after the final pour (not three)
A simple, repeatable pour structure:
- Bloom: 50g water for 30–45 seconds (wet everything)
- Main pour: up to 150g with a steady spiral
- Final pour: up to 250g, steady and calm
The goal is repeatability, not performance art.
Lever 3: Water temperature (a tidy finishing tool)
Temperature nudges extraction, especially for lighter roasts.
If your coffee tastes sharp and underdeveloped: go a touch hotter.
- From 94°C to 96°C (or pour a little sooner off the boil)
If your coffee tastes harsh and drying: go a touch cooler.
- From 94°C to 92°C (or wait a bit longer after boiling)
Don’t use temperature to fix everything. It won’t rescue a wildly wrong grind.
Lever 4: Ratio (use it to shape “strength”, not to fix faults)
Ratio affects perceived strength and body.
- If the cup is too intense but well-balanced: add a bit more water (e.g. 15g → 270g)
- If the cup is too light but well-balanced: use a slightly tighter ratio (15g → 230–240g)
If the cup is sour or bitter, ratio changes can just make the fault louder. Fix extraction first.
A quick decision table (print it, stick it on the cupboard)
Sour + thin
- Grind finer
- Keep pours steady; don’t “panic swirl”
- Slightly hotter water if needed
Bitter + drying
- Grind coarser
- Reduce agitation (gentler pour, less swirling)
- Slightly cooler water if needed
Weak/hollow (not sour, just empty)
- Slightly finer grind
- Increase controlled agitation
- Tighten ratio a touch (optional)
Flat/dull (no sparkle, no sweetness)
- Check water (hardness/filters)
- Check coffee age after grinding (pre-ground goes dull fast)
- Increase agitation slightly before you chase grind changes
Two advanced gremlins that waste a lot of time
1) Grind distribution (boulders + dust)
If your grinder produces a mix of very fine and very coarse particles, you can get a confusing cup: bitter edges with a sour centre.
What to do:
- Reduce agitation (fines clogging is magnified by turbulence)
- Consider sifting only if you enjoy hobbies that look like spreadsheets
- If you’re upgrading kit, grinder quality helps more than almost anything else
2) Water quality in the UK (especially very hard areas)
Hard water can mute acidity and make bitterness more prominent. Very soft water can make coffee taste oddly sharp and empty.
If you’re in a hard-water area, try a simple test:
- Brew once with your usual tap water
- Brew once with filtered water (jug filter) or a known “balanced” bottled water
If the second cup suddenly has sweetness and clarity, you’ve found a lever that’s worth keeping.
The calm method: three brews to fix 90% of problems
If you want a tight little troubleshooting loop:
- Brew your baseline. Write one sentence: “The problem is X.”
- Change only grind size in the correct direction. Brew again.
- If it’s improved but not perfect, adjust agitation (gentler or more purposeful). Brew again.
By brew three, you’ll usually be in the zone.
And once you are: stop tinkering. Make coffee. Enjoy it. The V60 is a dripper, not a moral test.