It’s best to dry herbs that have pronounced flavors and tough or needle-like leaves — such as rosemary, thyme, sage, oregano, lavender, mint and bay. Freeze herbs with more subtle flavors and tender leaves — such as parsley, cilantro and chervil. Preserving basil is the exception: It dries well, but its flavor is brighter if frozen.
For best flavor, harvest herbs just before they bloom, which is when their essential oils are at the highest level. To dry, fasten together small bunches of stems with twine or a rubber band, and then hang them upside down in a warm, dry place. Tie the bundles tightly, because the stems will shrink as they dry. When the leaves become brittle, strip them from the stems and store them in jars. Label and date the jars.
Follow these steps to preserve basil and other herbs by freezing:
Coarsely chop the leaves and then pack them loosely in ice cube trays.
Add water and freeze.
When the cubes have frozen, remove them from the trays and store them in plastic freezer bags for up to three months.
Add the cubes to sauces or soups for summertime flavor. Or, gently purée the herbs along with a small amount of olive oil (one-quarter cup oil to 1 cup of leaves) and then freeze the paste in a plastic freezer bag.
Cut off the amount of paste you need to flavor soups, sauces, dressings or marinades.