All herbs can be dried, but not all of them are worth the trouble. Parsley, chervil, chives, and coriander, to name four popular favorites that are widely marketed in dried form, taste more or less like hay that way, no matter how carefully they have been processed. Most of the others, including basil, dill, thyme, rosemary, sage, and tarragon, come through very nicely — changed, to be sure, but still useful.
I’m a bit of a romantic so I like to dry my herbs the old-fashioned way: hanging them in bunches in my dry basement. The scent is heavenly when several different bundles of herbs are drying together.
Most herbs have the strongest flavor right before they start to form flower buds. They should be freshly picked, preferably in the morning as soon as the dew has dried. (Basil, however, is an exception. It’s more flavorful at the end of the day.)
If the herbs have long stems with sparse foliage at the bottom, you can hang them in bunches. Use rubber bands or twine to tie loose bundles of eight stems or so. Hang them in the chosen spot (dark, dry, warm area that gets plenty of air circulation), and keep checking on them. If the herbs have tightly packed leaves (or flowers) that might rot before they could dry, strip them from the stems and spread them on screens. Prop the screens on piles of books or bricks so air can circulate.
Over the past several years, many methods of drying herbs have arisen (including spreading them on a towel in the back seat of your car when it sits out on a hot day). I found a website that details six methods of drying — depending on the amount of time and money that you want to spend. Visit Mother Earth News for some ideas.
No matter which way you dry them, the herbs are ready to store when they are brittle and should be removed from the drying area as soon as this happens. Strip the leaves from the stems, but leave them whole. Store in air-tight glass jars in a cool, dark, dry place for up to a year. Color is a clue: a pale look probably means a pale taste.