Published May 1, 2004.
Is it worth the trouble? Yes. And it’s no trouble at all if you choose the right grinder.
To prove our point that fresh-ground spices improve dishes, we recently conducted two tests. We baked plain pound cakes flavored with cardamom and simmered savory chutneys flavored with cumin, coriander, and cardamom, blind-tasting samples prepared with freshly ground and preground supermarket spices side by side. The fresh-ground spices won a decisive victory for their superior aroma, vibrancy, and roundness of flavor.
The test kitchen standard for grinding spices is an inexpensive blade-type electric coffee grinder (which we use for spices only, reserving a separate unit to grind coffee), but we had never put it up against other devices designed specifically for the task. Could we be missing out on something? We assembled a variety of models, looking for a grinder that would produce the most delicate, uniform powder and that was easy to both use and clean.
First up were the dedicated spice grinders. Like pepper mills, they are torsion-operated, meaning that you twist one part of the device (a glass or plastic jar loaded with spices) while holding a second part steady (a grinder housing screwed to the jar). The grinding mechanism consists of a rotating, grooved "male" head that fits into a stationary, grooved "female" ring. Wider grooves where the two meet break the seeds and feed the pieces down into finer grooves that grind them.
Many manufacturers tout grinding mechanisms made of ceramic, which is said to be superhard and corrosion-resistant. Despite these alleged advantages, we found that these models clogged easily with spice residue, essentially stopping the output of ground spices. The same was true for steel mechanisms. That, added to the exhausting, frustrating, endless twisting required to wrest ground spices from these units, made testing six of them consecutively seem like an act of masochism. On the whole, we'd skip torsion-operated grinders altogether.
Next up were three versions of the age-old mortar and pestle, including a Japanese suribachi with a textured grinding surface to help break down the contents. As a group, these were no more effective than the torsion-operated grinders. While the action required to work a mortar and pestle was less stressful than the repetitive motion required to work the torsion-operated grinders, it was still too much effort considering the disappointing piles of bruised, mangled seeds that we produced.
Last up were the electric coffee grinders, which were, in short, like breaths of fresh air. The only physical exertion required to use them was pressing a button. No stress, strain, or sore forearms, and they produced consistently good results on all of the test spices. And it only got better: The coffee grinders were easy to brush or wipe clean (just mind the blade!), easy to control for texture of grind, and no more expensive than the manual grinders and mortars and pestles.
To narrow the field further, we ground on to compare the four models' performance grinding spices in three amounts: small (1 teaspoon), medium (1 tablespoon), and large (1/4 cup). The four blade-type electric grinders whizzed through the tests with flying colors, producing fine powders from each amount of each spice. Only the lone burr mill, which worked like a motorized pepper grinder, failed to grind the spices finely enough, even when adjusted to its finest setting.
The tests did leave us concerned about overheating from the spinning blade of an electric grinder would effect the spices’ flavor. Taste tests of chutney and cardamom cake showed only very subtle differences between manual and electric grinders. We concluded that there's no need to worry about overheating spices in an electric grinder.