The finer you crush, grind, or mill spices, the more powerful and pervasive their effect on the finished dish will be. Freshly ground spices have a fresher, "sweeter" flavor than off-the-shelf ground spices. This is especially true with cinnamon, cloves, and nutmeg. For the subtlest effect, use spices whole; for more flavor, bruise or crush them lightly; for the most impact, grind them finely.

Roasting and Toasting Spices
Heat whole spices in a dry pan to release their natural volatile oils and bring out optimal aroma and flavor. Use a small, heavy skillet. Add the whole spices (roasting ground spices tends to turn them bitter, so is best avoided) and place over a gentle heat. Shake the pan, or stir with a wooden spatula, to keep the spices on the move, and toast gently for 1 to 3 minutes.

Some spices—like mustard and poppy seeds—"pop" when they are ready, others darken. The essential sign is that the spice becomes aromatic and smells toasty. Tip into a bowl to cool before grinding.

Grinding Spices
A mortar and pestle are the best tools for coarsely crushing spices, and many people think using this method releases a better, gentler flavor than using an electric mill. But it is difficult to crush such hard spices as cinnamon and cloves in a mortar. A small, deep mortar is better than a wide, shallow one, from which the spices tend to shoot out.

A coffee grinder crushes most spices, especially tough, woody ones, such as cinnamon and cloves. Clean the mill afterward by grinding a small piece of bread or a couple tablespoons raw rice. For cardamom- or cinnamon-flavored coffee, grind a cardamom pod or a 1/2- to 1-inch piece of cinnamon stick with the coffee beans.

Bruising (barely breaking the outer seed coat or husk) enhances flavor and aroma by allowing the flavor of the inner seed to work its magic. Bruise soft spices like cardamom pods and juniper berries by pressing down with the blade of a chef's knife.

To make spice pastes, roast and grind the dry spices first before adding the wet or fresh ingredients. This lets the spices properly incorporate.