If you're reading this post, you're a committed quality-coffee-drinker or at least, a budding one. Your next investment, as any aficionado worth his salt will tell you, is just as important: a grinder. Grinding the beans just before brewing your coffee—as opposed to days in advance—will help the coffee last longer and ensure a tastier cup.
But as with beans, espresso machines, and baristas, all grinders aren't created equal. A uniform grind, for one thing, is essential for optimal coffee extraction. Even the highest-quality brewed coffee will taste bitter or sour with uneven grounds. Look around and you'll find a wide array of sizes, shapes, and prices. So just how do you know which one is best for you?
We're happy you asked. Basically, grinders fall into two categories: blade and burr. A blade grinder operates much like a blender—simply fill it with beans and press the button using pulse-like spurts. The length of time the blades spin determines the size of the grind; the longer you pulse, the finer the particle. Unfortunately, uniformity is not the blade's strengths, especially if you need a courser grind—say, for French press or pour over. On the upside, a blade grinder won't break the bank (think tk to tk) or require a lot maintenance and care.
The burr grinder works in a different way, using cone-shaped or flat-bladed burrs that crush the beans between ceramic or steel plates. This allows for very precise control over the size of the grind. The burr also produces less heat during the process, which is believed to produce a better cup of coffee. If you're pressed for space or on a tight budget, you might consider a manual burr grinder, which tend to be smaller and less expensive than their electric-powered counterparts. (One to try: the $30 Hario Coffee Hand Grinder Skerton.) However, with espresso, you should be brewing within 30 to 45 seconds of grinding to prevent oxidation, so a manual version may not get the job done quickly enough.
Bottom line: if coffee has become a passion, go with an electric-powered burr grinder. They run the gamut in price ($130 to $2,000) and quality, depending on what you're looking for, so shop around. The general rule of thumb when buying one is to go for one with larger grinding burrs, heavier overall weight, and a low speed grind. A few that fit the bill: the Baratza Virtuoso and Baratza Preciso, the Rancilio Rocky, and the Breville Smart Grinder Pro.