Final answer:
Varietal aromas originate from the essential oils and aromatic compounds concentrated in various parts of plants. Their aromas are released when spices are ground and are most potent when fresh. To preserve these aromas, spices should be stored in sealed containers.
Step-by-step explanation:
Varietal aromas come from the essential oils and aromatic compounds present in spices and other plant materials. These aromatic compounds can be found in different parts of the plant such as the roots, shoots, fruits, bark, and leaves. The flavor of these oils and compounds can vary with the quality and freshness of the spice.
These aromas appear when spices are processed and ground, which releases their volatile oils into the air. However, once exposed to air, the aromas can dissipate, which is why ground spices lose their odor or flavoring over time. To preserve their aromas, spices should be stored in sealed containers. Whole beans or seeds have a longer shelf life and retain their aromas better than ground spices, but they too should be stored in sealed containers to maintain freshness.