Hyssop is valued above all for its rich aroma, which comes from natural essential-oil compounds. These are the first to suffer from improper storage.
- Container. After opening the pack, transfer the herb to an airtight jar — glass or food-grade plastic with a tight lid. This will protect it from moisture and foreign odours.
- Place. Store away from direct sunlight, sources of heat (cooker, radiator) and moisture. A dry, dark cupboard or pantry is suitable.
- Neighbours. Do not keep it next to strong-smelling spices or foods: dried herbs readily absorb other odours.
- Shelf life. Go by the date given by the manufacturer on the pack; over time the intensity of the aroma and flavour decreases.
A simple way to check freshness: rub a pinch of the herb between your fingers — good-quality hyssop immediately gives off its characteristic spicy smell. If the aroma is weak or absent, the infusion will also be less expressive.