My research lead me to two different possibilities for preserving the herbs I'm growing on the balcony this summer. The traditional method is by drying herbs, which you can do in a variety of ways. The method with the quickest and best results is by using a food dehydrator, which circulates air through trays. A quick search on Craigslist found 3 different dehydrators for sale in my area, all under $20. However, since I am still living a fairly transient lifestyle (moving in a month, actually!), I don't think I'm going to rush out and buy a dehydrator. I remember my mom buying one when I was younger, determined to use it to create healthy, tasty snacks for us kids. I think she only used it a few times, and it sat gathering dust in a cupboard before a kitchen renovation sent it on its way. Since you can achieve satisfactory results without buying any special equipment, I plan to try drying them by hanging them.
Gather the herbs on their stems and strip the leaves off the bottom inch or two. Remove any dead or damaged leaves. Group the stems in small bunches and tie or rubber band them together. Then, hang the bundles upside down in a warm, dry place with lots of space between bundles to make sure the air circulates. Check on them periodically, because as the herbs dry the stems shrink, and you may need to re-tie the bundles so that none of your branches fall out. Another option for drying, if you have the space, is to lay the branches out on horizontal window screens (elevated so the air circulates). You will still need to rotate the stems periodically.
One of the main problem areas in preserving herbs is that they mold and rot before they dry. This happens when there is too much moisture in the herbs or on the outside of the herbs. When you harvest them, if they are clean, do not wet them. If they are dirty or dusty, rinse them under water, and shake or pat off excess water. Take the time to dry the stems off completely to prevent mold.
The success of your drying depends also on the types of herbs you are preserving. The method above works best for thin-leafed and delicate herbs such as Bay, Dill, Marjoram, Oregano, Rosemary, Summer Savory, or Thyme. However, herbs with thicker, more moisture-retaining leaves can also be frozen. Freezing herbs retains the same flavor that drying does, however, they won't be suitable for garnish, only for cooking. Freezing is recommended for things like Basil, Chives, Mint, Tarragon, Parsley, Fennel, or Chervil. Remove the stems, chop if you wish, or leave the leaves whole. Lay the dried herbs out in a single layer on cookie sheets or trays and place in the freezer. Once the herbs have completely frozen, place them in containers and store in the freezer. You can also freeze individual portions of herbs by making ice cubes out of them. Prepare your herbs by removing the stems and chopping, and then pack them into ice cube trays. Cover with water and freeze. When frozen, remove the cubes from the trays and store in freezer bags. When cooking with them, you can toss the whole ice cube right into the pot! A few sites I looked at recommended blanching the herbs before freezing to help retain color and flavor.
I found lots of good resources for preserving herbs. Much of the information above came from these sites! Please visit them for further reading and information.
Harvesting and Preserving Herbs for the Home Gardener
How to Preserve Herbs