When you want freshly ground spices at home—for, say, a batch of channa masala—you have a few options. You can get an electric spice grinder, or buy a second coffee grinder devoted uniquely to turning whole spices into powder. Or, if you have the time and energy, there’s always the tried-and-true mortar and pestle.
But unless you grind spices every day, it probably isn’t worthwhile to invest in special spice-grinding paraphernalia. This doesn’t mean forswearing freshly ground cumin, coriander, cloves, mustard seeds, allspice, and cinnamon, however. You can grind spices in a regular blade coffee grinder without tainting it forever. Here’s how to clean out a coffee grinder so that your curry doesn’t taste like coffee and your coffee doesn’t taste like curry.