A spice is a dried seed, fruit, root, bark, or vegetable substance primarily used for flavoring, coloring or preserving food. Sometimes a spice is used to hide other flavors. Spices are distinguished from herbs, which are parts of leafy, green plants also used for flavoring or as garnish.
A spice may be available in several forms: fresh, whole dried, or pre-ground dried. Generally, spices are dried. A whole dried spice has the longest shelf life, so it can be purchased and stored in larger amounts, making it cheaper on a per-serving basis. Small seeds, such as fennel and mustard seeds, are often used both whole and in powder form.
The flavor of a spice is derived in part from compounds (volatile oils) that oxidize or evaporate when exposed to air. Grinding a spice greatly increases its surface area and so increases the rates of oxidation and evaporation. Thus, flavor is maximized by storing a spice whole and grinding when needed. The shelf life of a whole dry spice is roughly two years; of a ground spice roughly six months. The “flavor life” of a ground spice can be much shorter. Ground spices are better stored away from light.
To grind a whole spice, the classic tool is mortar and pestle. Less labor-intensive tools are more common now: a microplane or fine grater can be used to grind small amounts; a coffee grinder is useful for larger amounts.
As a general rule, the flavors from a spice take time to infuse into the food, so spices should be added early in preparation.
Vegan recipes often use more spice than conventional recipes, since spices are plant-based and a great way to add flavor to a non-meat dish. It can be tricky to cook a full range of recipes under strict limitations, but with a little creativity vegan food can be as delicious and satisfying as any other diet.