Roasting spices isn't hard, but doing it well requires involvement of your senses and some timing. It's a bit of an art, in fact — a fun and easily accessible culinary art.
- Use a small, heavy pan (cast iron works well) or a wok. (In India, where the technique is commonly used, cooks use a pan called a tava for roasting spices and making flat bread.) Place your spices in the dry pan shake or stir them with a wooden spoon while they roast. You want to heat the spices slowly, so that they warm clear through to the center of the spice without burning the outside, so use low to medium-low heat.
- How long it takes to roast a spice depends on the spice (how big and/or hard it is), how much heat you use, and the pan. Be careful not to burn the spices or they'll become bitter. They shouldn't smoke at any time during the process.
- You'll know the spices are ready when they smell rich and full-bodied and become slightly darker in color. They'll be aromatic as soon as they hit the pan, but wait just a bit and that aroma will fill the air as the spices brown. The goal is to roast them through — not just on the surface — but without burning them. This usually takes just minutes. You may hear a little popping sound as the whole spices roast.
- Whole spices are preferred over ground spices for roasting. That's because whole spices better retain their natural oils and so contain more flavor to release when they're heated or ground. You can certainly roast ground spices — just keep in mind that it will take only seconds before they're done.
- Once your spices are roasted, move them from the pan to a bowl or plate to cool. To grind the cooled spices, you can use a mortar and pestle or a spice grinder or coffee grinder. You'll find that roasted spices are easier to grind than unroasted spices. You get the best flavor when the spices are used immediately, but you can store most in a tightly covered jar for a few weeks without too much deterioration.
- You can also roast spices in the oven, though this method is somewhat less efficient since you have to heat the oven instead of using only minutes of heat on the stovetop. Spread the spices on a dry tray and roast at 326 degrees F until they're fully aromatic and slightly darker.
- When roasting blends, start with the spice that needs the longest cooking time first and add the others in order of how quickly they roast. If you're including ground spices, add those just before you're done.