What a grinder actually does
Brewing coffee is controlled extraction: hot water dissolving the good parts of the bean while leaving the harsh parts behind. The single biggest lever you have over that process is particle size, and particle size is entirely the grinder's job.
A good grinder produces particles that are mostly the same size, so they extract at the same rate. A poor one produces a mix of boulders and dust. The dust over-extracts and turns bitter, the boulders under-extract and turn sour, and you end up with a cup that is somehow both. No machine downstream can fix that, because the damage happened before the water arrived.
The blade grinder problem
Blade grinders do not grind, they smash. The blade whirls until you let go of the button, which means the result is a lottery weighted towards dust. If you own one, the honest advice is to stop using it for anything you care about. Even pre-ground coffee from a roastery, ground properly on a shop grinder the day it ships, will beat it.
A £150 grinder feeding a £100 machine makes better coffee than a £50 grinder feeding a £1,000 machine. We have run that exact taste test at the bar. It is not close.
What to buy at each budget
Around £40: a hand grinder
A decent hand grinder with steel burrs is the best value in coffee. Thirty seconds of cranking for a V60 or cafetiere, and a grind quality that embarrasses electric grinders at three times the price. This is where every home setup should start.
Around £150 to £250: an entry burr grinder
A motorised flat or conical burr grinder with proper adjustment opens up espresso, where grind changes of a fraction of a millimetre matter. Look for stepless or fine-stepped adjustment and a burr set you can buy spares for. Ignore anything sold on the strength of an app.
£400 and up: single dosing
At this level you are buying consistency and workflow: weigh in, grind, nothing left in the chamber going stale. Lovely to own, but the jump from blade to burr is a cliff; the jump from good burr to great burr is a kerb.
Whatever you buy, do these two things
- Grind just before you brew. Ground coffee loses its aromatics in minutes. This is most of the reason fresh whole bean tastes so different.
- Keep it clean. Old grounds and coffee oils go rancid in the burrs. A brush-out once a week costs nothing and tastes like an equipment upgrade.
Bring your grinder questions to the bar any day we are open, or book a Saturday cupping session and taste the difference side by side. Your machine is probably fine. Your grinder might be the story.