How do I make my coffee less bitter?

A harsh, drying bitterness almost always means you pulled too much out of the coffee. That is over-extraction: water keeps going past the sweet, balanced flavours and starts dragging out the heavy, bitter compounds that come out last. The fix is to make the water work a little less hard. Change one thing at a time so you know what helped.

Pull less out of the grounds

These are the levers, in rough order of impact. They are four of the-four-dials.

1. Grind coarser. The biggest lever. Bigger particles have less surface area, so water extracts less. If the cup is bitter, going a step coarser usually helps right away. See the grind-size-guide.
2. Use slightly cooler water. Try around 90 to 93C (194 to 199F) instead of a full rolling boil. Very hot water extracts aggressively.
3. Shorten the brew. Less contact time means less extraction. Pour faster, stop a pour-over sooner, or steep a French press for less time.
4. Check the ratio. Too little water for the amount of coffee can taste muddy and bitter. Loosen it slightly toward the standard ratio if you have drifted strong.

Make sure it is really bitter

Bitterness and sourness pull you in opposite directions, so it helps to be sure which you have. Bitter is the harsh, lingering, drying taste; sour is the sharp, tart, almost-lemony one. If you over-correct and the cup turns sour, you have swung into under-extraction and should grind finer or brew longer again. The full guide is sour-vs-bitter.

When the beans are the cause

Sometimes your technique is fine and the coffee itself is the problem.

• Dark roasts taste roasty and bitter by design. A medium roast may simply taste sweeter with no other change.
• Stale beans read as flat and bitter. Check the roast-date and buy fresher.

Dial the brew first. If bitterness survives a coarser grind and cooler water, blame the beans. For a deeper walk-through, see why-is-my-coffee-bitter.