Throw Away Your Blade Coffee Grinder
You can throw it overhand, as if it was a ball and your trash can was the basket. Or you can throw it underhand. Bonus if you've got a brick wall next to the trash can to serve as a backboard. Better yet, if you hold it by the cord, you can swing it around over your head and fling it at your enemies.
Or take a Sharpie and write on it in big capital letters: "NOT FOR COFFEE" and use it for spices or salt or on the soft fleshy parts of your captured enemies.
Just don't use it for coffee.
Now, I'm sure I've already offended some folks. People tend to get offended any time you say something bad about the way they make or drink coffee. It's the other edge of the double-edged sword that is working as a coffee professional: it's really fun to work with coffee because people really love coffee, but that love often comes with habits and traditions that people aren't eager to give up, much less hear you talk trash about.
A lot of what's changing at the leading-edge of specialty coffee is the result of a coordinated improvements in cultivation, processing, and handling at certain coffee farming areas, and roasting, freshness-standards and brewing at the other end of the value chain. If the raw materials aren't of high quality, what's the point of getting all precious about the intricacies of brewing? If the brewing process is haphazard and crude, why invest in better growing and cultivation practices?
That's why blade grinders were just fine for commercial-grade, grocery-roast, best-if-used-by 9-months-out coffee. Even if you whipped out a $3000 Mahlkonig EK43 grinder, you wouldn't taste much of a difference in the cup. On the other hand, no matter how high-quality fancy-pants you get for your whole bean coffee choices, if you're grinding with a blade grinder, it's like watching HD Blu-ray movies on an old 1980's 15-inch tube TV (no offense to those who watched "Fast and Furious 6" just for the dialogue).
So what's wrong with a blade grinder, and what's so great about those high-falootin' burr grinders? To cut to the chase, grinding coffee with a blade grinder is a lot like chopping your fruits and vegetables with a mallet.
When we say "grinding," what we mean is getting things down to more numerous, smaller things. The technical term is "comminution." But if you consider what that process actually involves, it's cutting, rubbing, mashing, crushing, smashing, smooshing, and any number of other double-entendres. Depending on the material we're dealing with, cutting will give us more precision, crushing and smooshing won't, and we want precision when we're grinding quality coffee. We're seeking a more precise grind profile.
When someone says "grind profile," think about it as a graph drawn out on paper, with particle sizes on the y-axis and quantity on the x-axis. You know, like the profile of someone's face, in this case, lying-down and face-up. Generally speaking, the best grind profile is the one that looks most like Pinocchio: a big peak at one particular size means a more precise grind size.
Every coffee brewing method is, whether anyone realizes it or not, optimized for a particular grind size. It's up to you to taste your way to tune your grinding, or adjust your brewing method, to align the two and get the most out of your coffee.
Because roasted coffee is fairly fragile and has a particular cellular structure already, you're going to get some amount of "fines," or the coffee equivalent of sawdust. Whereas sawdust gets swept or vacuumed away, unless you choose to sift them out, the fines will brew alongside the more properly-sized coffee bits. Those fines will over-extract, resulting in bitter, unpleasant flavors. Some grinders, by the way they grind, produce more fines than others, and a blade grinder makes the most of all.
That's why a blade grinder is like trading your chef's knife for a mallet. The blade grinder relies on the little propeller-like "blade" to spin, pulverizing the coffee it encounters into smaller and smaller bits. There's no control involved, aside from how long you turn it on for. Sure, shaking it as you use it helps keep stuff from accumulating in the corners, but if all you had was that mallet to "cut" with in the kitchen, even the dullest of knives would be a huge improvement. Similarly, any burr grinder would be an improvement over a blade grinder.
When I'm sizing up burr grinders in a store where it isn't exactly practical to do a test-drive, I'll ask a store employee to let me inspect the burrs. Either they'll help me do it, or I'll get permission to get into it myself. This usually involves removing the bean hopper and opening the top, stationary burr. (Some grinders have vertically-oriented burrs, which means inspection is more involved because it means removing the front face.) Good burrs have sharp cutting edges, are milled (meaning the edges have been ground from a solid piece of metal), and have smoother flat surfaces. Poor quality burrs are molded (instead of milled), have dull or few sharp cutting edges, or have rough texture to the surfaces that will rub against the coffee.
Some brands that have high-quality burrs on their higher-priced models are Baratza, Breville, and KitchenAid. But anything's going to be better than a blade. Save that whirly-bird blade thing for spices and herbs, though in most cases a mortar and pestle will be better as well. Poor whirly-bird, nobody likes you!
Have you upgraded from a blade to a burr grinder? Share your experiences in the comments!
About the author:Nicholas Cho is the co-founder of Wrecking Ball Coffee Roasters in San Francisco, and produces and hosts the Portafilter.net Podcast for Coffee Professionals. Follow him on Twitter at @nickcho