Our list mostly includes Cone-burr mills. In a cone grinder, coffee beans are ground and ground between two burr rings. They offer a better, more consistent grind than you’d expect to find with a traditional blade grinder, even the finest ones.
Flat-burr mills They are similar, but usually more expensive. In these, the buros are spread over each other, and the beans pass through when they are ground. Instead of relying on gravity like a cone-burr grinder, the grinding action removes the ground from one end, and the beans spend more time in contact with the burrs. This results in a more uniform grind, but for home brewers, the cone-burr grinders are just as good—though they require more maintenance and don’t result in consistent micron-scale grounds.
Blade grinders As a cook, have a rotating cutter. But the knife doesn’t do anything. Some of your coffee will be fine powder on the bottom, and you’ll have bits on top that are too big even for a French press. The result is an inconsistent, unrecognizable brew. These grinders are cheap, and yes, using fresh beans in a cold grinder is much better than buying ground coffee. (You can even learn how to shake the beans to grind them up a bit. For more knife grinder hacks, check out World Barista Champion James Hoffman’s video.)
If you can afford it, we highly recommend going with the burr grinders we’ve listed. There’s a reason you pay less than a budget burr grinder. The machinery in a high quality burr grinder is a bit more complicated, and is built to withstand more wear and tear. In cheap burr grinders, the burr dulls from regular use, and flasher motors can burn out within months of regular use.
PSA: Do not put ground coffee into a burr grinder. Logically, it is reasonable. It’s too rough, so you put it back in, right? No! With a burr grinder, the ground coffee gets stuck in the bags, and you need some disassembly to get them back to rights.