Why does my coffee taste different every time?

Consistency is not about precision for its own sake. It is about being able to tell whether a change you made was an improvement, which is impossible when the baseline moves on its own every morning.

What you'll need

• Scales
• Timer (optional)
• Thermometer or a kettle with temperature control (optional)

Step by step

1. Weigh the coffee rather than scooping it.A scoop of coarse grounds and a scoop of fine grounds differ substantially in weight. This is the single largest source of day-to-day variation.
2. Weigh the water too, or fill to a mark.Water is easy to eyeball wrongly, and the ratio is what decides strength. 60g of coffee per litre is a reasonable starting point for filter.
3. Use the same grind setting, and check it has not drifted.Burr grinders drift slightly with use and temperature. Blade grinders produce a different result every time by design.
4. Control the water temperature.Just off the boil, around 92-96°C. Boiling water scalds the grounds; water that has sat cooling under-extracts.
5. Keep the brew time roughly the same.For filter, aim for a consistent total time. Wildly different pour speeds change extraction more than most people expect.
6. Store beans properly and use them within a sensible window.Airtight, away from light and heat, not in the fridge. Coffee is most predictable between about a week and a month from roasting.

Tips

• Change one thing at a time. If you adjust grind and ratio together and it improves, you have learned nothing useful.
• Water matters more than most people expect. Very hard or heavily chlorinated tap water is worth filtering — the difference is not subtle.
• Rinse paper filters with hot water first. It removes the papery taste and warms the brewer, which also stabilises temperature.

Common mistakes

• Measuring coffee by scoops — Scoop weight varies with grind size and how the beans settle, so the ratio changes without you knowing.
• Buying pre-ground coffee and blaming the technique — Ground coffee stales within days. No amount of careful brewing recovers it.

Questions people ask