Blade Grinders: What They Are And When To Use Them For Your Coffee Beans

If you buy your coffee beans whole, you probably know that experts recommend grinding them just before you brew, and it's not just for the pleasure of the ritual. There are scientific reasons why coffee tastes and smells better when freshly ground. The next logical question becomes what to grind them with. Sure, you could go old-school with a hand-cranked machine or upscale with a fancy burr grinder like the coffee shops use, but most people who buy whole bean coffee use a blade grinder.

This small, inexpensive, and widely available tool is about as simple as it gets: just a small compartment for the beans and a single blade that spins around when you turn it on. If you've ever used a string trimmer in your garden, the concept is similar. The blade slices through whatever it encounters, whether that's a whole bean or a chunk that's already been cut. You may notice that the particles are not very uniform, and the machine doesn't have a way to control the size. Basically, the longer you grind, the smaller the particles get.

So it's not the most precise instrument, but that doesn't mean you can't make good coffee with a blade grinder. One of the things you can do to improve your results is to grind fewer beans at a time. When the beans aren't crowded in, they can move more freely around the compartment, especially if you pause between pulses and shake the beans. This helps the blade cut them up into more uniform pieces instead of turning some into dust (which can over-extract the flavor, creating bitterness or blandness) while leaving others too coarse (which under-extracts the flavor, creating sour or acidic tastes).

The other secret is to choose a type of beverage and brewing machine that's compatible with the size of grounds your blade grinder can produce. Running a blade grinder for 5-10 seconds will give you coarse, sea salt-sized pieces that work well for French presses or old-fashioned percolators. A few more seconds will produce sand-sized, medium particles compatible with pour-overs and drip pots. Experts don't recommend using this grinder for espresso, as it's too difficult to achieve the fine, uniform particles that you need. Instead, keep your blade grinder for your daily pot, and head out to a shop when you're craving espresso.