A heavy, metal base is an indicator of quality, and will remain steady on the counter.
Conical burrs grind coffee evenly without heating, making them ideal.
Larger coffee grinders are reliable and convenient, but are more expensive than smaller ones.
A machine that grinds coffee slowly will preserve the most flavor and aroma.
Glass canisters reduce static cling and prevent caking.
The minute a coffee bean is cracked or ground, the volatile aromatics that give a cup of coffee its flavor begin to evaporate. A good cup of coffee can not be made without fresh ground coffee beans. The stuff in the tin is fine for those who brew a pot just to get their morning fix, but if you really want to enjoy the coffee you make at home, grinding your own beans is the only way to go. This is especially true if you own an espresso machine or a french press.
All coffee grinders in today's marketplace fit into one of two categories. Chopping or blade grinders work like miniature blenders, chopping the beans with blades that revolve at high speed. Blade grinders are ideal for grinding dried herbs and spices, but they should never be used for grinding coffee. Blades heat the beans damaging flavor and aroma, produce uneven grinds, and create coffee dust that can clog the delicate filters of espresso makers.
Burr grinders, which essentially mill the coffee, grind by crushing beans between two metal plates. They generate little heat while grinding and can consistently produce an array of very coarse to very fine grounds. The most zealous coffee enthusiasts still use hand-cranked grinders, but we believe electric grinders work just as well. They are easy to use and produce high quality grinds quickly and at the touch of a button.
Burr grinders themselves can be subdivided into two distinct categories. Disk burr grinders utilize two flat textured plates to grind coffee in the same way traditional grain mills use stones to grind flour. Disks often spin at high speeds producing even grinds quickly and efficiently, but they heat the beans more than conical burrs. Disk grinders are ideal for processing quantities of coffee, but at a slight sacrifice of aroma and flavour.
Conical burr grinders essentially work like pepper mills with a convex plate revolving inside a convex one. Conical burrs grind coffee more slowly than disk grinders, but they not only transfer less heat to the beans, they can produce finer grinds as well. Disk grinders are ideal for commercial environments, but we recommend purchasing a grinder with conical burrs for everyday needs. Conical grinders will give you more control over the texture of your grinds, and your coffee will remain of the highest possible quality.
The marketplace offers burr grinders in a variety of sizes. Smaller, less expensive burr grinders are ideal for tiny kitchens as they are easily stored. They do require constant refilling, most holding just enough beans for a pot or two of coffee, and they sometimes have trouble producing either very fine or very coarse grinds (though the techno-savvy will sometimes find the burrs easy to recalibrate).
Larger, professional grade grinders are bulky and expensive. They will generally offer a wider range of grind settings, produce consistent grinds fine enough for Turkish coffee and coarse enough for a french press, and hold enough beans in the hopper for a week's worth of coffee. If you brew regularly, and you have the space for it, we think the quality and convenience offered by larger grinders are unbeatable.
Two other factors worth considering in purchasing a coffee grinder are the speed at which coffee is ground and how easy the machine is to clean. The slower the machine grinds, the less the machine damages the beans. We recommend looking for a machine that grinds at 500 RPM or less. You will also want a machine that allows easy access to and removal of the burrs for cleaning. Oils will build up in your machine over time and turn rancid, affecting the quality and taste of your coffee.
Grinders with glass hoppers and grind canisters are ideal. Glass holds little if any static, making grinds easy to remove and preventing build up. Plastic canisters will quickly cake up with coffee dust and turn rancid, especially when grinding fine for espresso. Canisters that seal tightly are also a plus and will save you cleanup time from spilling and leakage during the grinding process.