Drying; freezing; under oil. It’s best to harvest herb leaves just before blossoming when they contain the maximum amount of oils. Gather seed heads when they are brown and ready to drop. Pick herbs early in the day; wash them; shake or pat them dry. To avoid having to wash herbs, hose them the day before picking.
To dry herbs, tie them in small bunches and hang them upside down in a warm, dark, well-ventilated spot, such as the attic. Or tie up the bunches in paper bags with ventilation holes and hang them outside in the shade for several days (bring them in overnight). Herbs can also be dried in an oven or dehydrator at 70°F to 100°F Use trays of wood or fabric stretched on a frame-not metal. A microwave oven is also suitable for drying herbs; see the manufacturer’s instructions.
When thoroughly dry, the leaves can be easily stripped from the stems and will crumble when crushed. Store the herbs in clean, airtight jars, preferably in a cool, dark place. They will keep about 1 year at the longest.
Herbs can also be frozen, a method particularly suitable for soft leaved types such as basil and chives. Tie them in small bundles, blanch them for a few seconds in boiling water, dip them in chilled water, then place them in plastic bags and freeze. They will keep for 2 to 6 months. To freeze for a shorter period, omit blanching; snip and freeze the leaves in plastic bags, or chop the leaves and put them in ice cube trays with water. When frozen, drop them in plastic bags.
Herbs for sauces can be kept several months under oil. Put snipped leaves in ajar, cover with olive or vegetable oil, and store them in the refrigerator.