Many people plant gardens not just for the fun but also to grow and preserve their own food. For those lucky enough to plant them, a regular gift from the garden are dried herbs. Drying is, in fact, the oldest method of food preservation. Drying also happens to be one of the easiest and safest methods of preserving food for later use.
There are four techniques for drying. They are using a food dehydrator, air drying, oven drying, and microwave drying. Michigan, with its high humidity, normally requires that herbs be dried using a mechanical means.
To dry herbs, you need to expose the flowers, leaves or seeds to warm, dry air. Sun drying is not recommended for herbs because the sun causes the herbs to lose color and flavor.
Harvesting herbs should be done early in the day just after the morning dew has dried but before the mid-day sun. For the herbs, select leaves from plants that are not in flower. The best flavor comes from plants that are in bud stage but have not flowered yet. Do not allow the leaves to lie in the sun after picking because they will wilt and lose flavor. Rinse the herbs thoroughly in cool water and gently shake the herbs to remove the excess water. Do not use bruised, soiled, or imperfect leaves and stems. These will have less than desirable flavor.
The best technique for drying herbs is a food dehydrator. It is the fastest, easiest way to produce high-quality dried herbs. Pre-heat the food dehydrator thermostat between 95 degrees Fahrenheit and 115 degrees Fahrenheit.
Once the herbs have been rinsed place in a single layer on the dehydrator trays. The times for drying may vary from one to four hours. They will need to be checked regularly. The herbs are dry when the leaves crumble easily and the stems break when bent.
While Michigan State University Extension does not normally suggest air drying, it can be done under certain conditions. Air drying needs to be done on a hot, dry (low humidity), day, or in a room that is hot and dry with an air current.
Sturdy herbs like parsley, rosemary, sage, summer savory, and thyme are the easiest to dry using the air drying technique. Simply tie the herbs into small bundles and hang them up to dry. Herbs can be air dried outside, but for better color and flavor indoor drying is best.
Tender leaf herbs such as basil, lemon balm, mints, oregano and tarragon will mold due to their high moisture content if not dried quickly. Try hanging these herbs and herbs with seeds in paper bags with holes in them. Punch or tear holes in the sides of the paper bag. Put together a small bunch of herbs inside the bag. Do not put together a large bunch because the herbs will mold due to lack of air circulation. Close the top of the bag with a rubber band. Hang the bag where there will be plenty of air circulation. As the leaves and seeds dry, they will fall to the bottom of the bag.
Oven drying is an excellent way to dry bay leaf, mint or sage. This technique allows the leaves to be dried individually. Remove the best leaves from the stems. Place the leaves on a paper towel to allow the towel to absorb the moisture. Do not allow the leaves to touch. Cover with another layer of paper towel and another layer of leaves. Using this technique, only five layers at one time should be tried. The oven should be very cool. A gas pilot light furnishes enough heat for overnight drying. The leaves will be flat and retain their color.
Microwave drying can be used when only a small amount of herbs is to be dried. Follow the instruction that come with the microwave.
When the leaves are crisp and crumbly between the fingers the herbs are ready for storage. Dried leaves may be left whole, or coarsely crumbled for storage. Store the herbs in airtight containers. Place the containers in a cool, dry, dark area to protect the color and fragrance of the herbs.