For our latest update to our ConsumerSearch report on coffee grinders, we selected three models that run the gamut from inexpensive to expensive. Our Best Reviewed picks carry over from the last update in 2008: the Krups Fast Touch 203 (*Est. $20), a blade grinder; and the Capresso 560.01 Infinity (*Est. $90) and the Rancilio Rocky Doserless (*Est. $350), both burr grinders.
Given the difference in price, it's worth discussing the difference between a blade grinder and burr grinder, so you can choose the best coffee grinder for your needs. Blade grinders, which are inexpensive and easy to use, use a spinning blade attached to a motor. Not only are blade grinders easy to clean, they can also double as spice grinders (as long as you clean them thoroughly between uses). Reviewers say they work well for automatic-drip coffee makers, which don't require a very fine or perfectly consistent grind. You can improve a blade grinder's evenness by grinding in brief bursts, stopping periodically to shake the grinder.
If you own an espresso machine, you'll need a burr grinder, as blade grinders simply cannot produce a fine enough grind. Burr coffee grinders are larger, heavier and more expensive than blade grinders. While a good blade grinder can cost $20, the price of a quality burr grinder starts at $90 and rises quickly. Burr grinders work like pepper mills, grinding a few coffee beans at a time between grooved metal disks. One disk rotates while the other remains stationary. There are two basic types of burr grinders: wheel grinders and conical grinders. Wheel models, which are cheaper and spin faster, can be noisy and messy. Conical burr grinders aren't as messy, noisy or prone to clogging because they grind more slowly, but they're pricey.
In professional tests, automatic-drip coffee made from burr-ground beans have a better mouth feel, but the trade-off is a slight bitterness. Experts say very finely ground coffee that's exposed to water for several minutes -- rather than the seconds it takes to pull an espresso shot -- can be overextracted, or leach bitter flavors into water. Coffee should be ground even more coarsely for French presses, which expose beans to water for longer periods than auto-drip coffeemakers
About.com's coffee and tea channel provides a coffee-grinding guide that describes different coarseness levels. A useful chart is included, which identifies the best coarseness for different types of coffee brewers. (Note: ConsumerSearch is owned by About.com, but the two don't share an editorial affiliation.)