The folks at Serious Eats know what they’re talking about. The following excerpt from Nick Cho’s article about the ubiquitous blade coffee grinder and grinding coffee is proof yet again that details matter.
So what’s wrong with a blade coffee grinder, and what’s so great about those high-falootin’ burr grinders? To cut to the chase, grinding coffee with a blade coffee 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.
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 coffee grinders, by the way they grind, produce more fines than others, and a blade coffee grinder makes the most of all.
That’s why a blade coffee grinder is like trading your chef’s knife for a mallet. The blade coffee 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 coffee grinder would be an improvement over a blade coffee grinder.
To learn more, read the full article online at http://drinks.seriouseats.com/2014/01/replace-blade-grinder-with-burr-grinder-best-coffee-equipment-advice.html.
A decent burr grinder doesn’t have to be super expensive. Clutch Coffee Roasters offers the Hario Skerton, one of the industry-standard hand-crank grinders, for just $45!