If you make one change to your coffee this year, make it this one. Buy whole beans and grind them just before you brew. It matters more than the machine, more than the water, more than almost anything else.

What happens when coffee is ground

Roasted coffee is full of volatile aromatic compounds, the things you smell when you open a fresh bag. Grinding shatters the bean into thousands of pieces and exposes all that surface area to air. The aromatics start escaping immediately and oxygen starts staling the oils. Within about fifteen minutes a noticeable amount of the aroma is gone; within a few days, most of it. The coffee still works, it just tastes flatter, duller and more bitter.

Whole beans protect themselves. The intact bean holds onto its aromatics for weeks, which is why a bag that's a month past roast can still taste great if it's been kept whole and sealed.

Grind size is the other half

Pre-ground coffee is ground to one size that has to suit everybody. Espresso wants a fine grind, plunger wants coarse, pour-over sits in the middle. A grinder lets you match the grind to the brew, and to adjust when a shot runs too fast or too slow. That control is the difference between coffee that's fine and coffee that's excellent.

Blade or burr?

A blade grinder chops beans unevenly, giving you dust and boulders in the same dose that extract at different rates. A burr grinder crushes beans between two surfaces to a consistent size. Burr is the one to buy. A good hand grinder starts well under $100 and will outperform most cheap electric grinders; an entry-level electric burr grinder suits anyone making several coffees a day. We stock both in manual grinders and electric grinders.

When pre-ground still makes sense

Plenty of people don't want another appliance, and that's fine. If you buy ground, buy smaller bags more often, keep the bag sealed and away from heat, and use it within two or three weeks. We grind to order for espresso when you ask us to, so it's as fresh as pre-ground can be.

The short version

Whole beans stay fresh; ground coffee doesn't. A burr grinder is the best value upgrade in coffee, and if you skip it, buy ground in small amounts and use it quickly.