Herbs are versatile plants: They are a source of flavor, fragrance, healing, and comfort. In Homegrown Herbs (Storey Publishing, 2011), Tammi Hartung provides step-by-step guidance for growing, using, and enjoying 101 different herb cultivars. The best and easiest way to preserve your herbs is to dry them, and in this excerpt from Chapter 7, Hartung describes how to dry herbs for optimum quality and storage life.
You can purchase this book from the MOTHER EARTH NEWS store: Homegrown Herbs.
There are a number of methods you can use to dry herbs, from hanging bundles to screen and basket drying to drying in paper sacks and cardboard boxes. Regardless of how you do it, be sure a plant is fully dry before storing or it will mold.
Attics usually work very well for drying herbs; basements generally aren’t good if they have poor air movement or are the least bit damp. I dry herbs on our covered patio here in Colorado, but the climate is dry. People in areas with high humidity will have more difficulty. You may need to assist the process by setting up fans to improve air circulation and remove some of the moisture from the air. If plants are dried improperly, they may show signs of mold and mildew in the form of a white downy or black slimy coating. The plants will often smell musty or rotten; these plants must be discarded.
Please do not dry herbs in buildings where machine oils or other fumes will be present. Plants can absorb these substances, and that’s the last thing you want if you plan to use them for health and well-being.
How to Dry Herbs in Hanging Bundles
If you decide to dry herbs by hanging them upside down in bundles, it’s important to pay attention to the size of the bundles. As you put together a bundle, look at the stems and be sure that the diameter of the bunch where the stems are tied together is no bigger than that of a pencil. This will allow for good airflow through the bundle, thus discouraging the growth of mold and mildew.
Hanging herbs should be tied with a simple slipknot or a rubber band. This keeps the bundle together as it shrinks during the drying process. If you use string tied in a basic knot, stems will fall out as the plants shrink.
Don’t place bunches of hanging herbs too close together; crowding produces poor air circulation. Bundles should be hung in an area that is protected from direct sunlight and moisture, where there is good warm-air circulation. Normally, bundles of herbs will dry in one to two weeks.
What about Ovens and Dehydrators?
I’m often asked if I dry herbs in a food dehydrator or in the oven. I don’t want to expose my plants to any temperature that would be above that of normal warm air; heat can change or degrade a plant’s constituents and nutrients. If you do choose a heat mechanism like a dehydrator, set it at the lowest temperature possible and check the plants often.
Hanging bundles of drying herbs add a beautiful touch to any space in your home that has good air movement, warm temperatures, and is not in direct sunlight.
How to Dry Herbs on Screens and in Baskets
When using screens to dry herbs, choose nonmetal (such as nylon) or stainless steel screening material. Aluminum screening can change the taste and fragrance of a plant as it dries, and there is also the potential that medicinal constituents will be altered. If you must use an aluminum screen, lay a barrier of cotton cloth or paper between the plant material and the screen. This will help protect the plants without preventing the movement of air.
Place the screen on blocks or hang it horizontally from the ceiling to allow air to move below, around, and above it. I simply prop my screen across two chairs. Place the screen out of direct sunlight and protect it from moisture. Plants will take from one to several weeks to dry on screens.
Basket drying is one of my favorite ways to dry small amounts of herbs. Select a basket that is shallow and has a weave big enough to let air flow through it but small enough that the plant material can’t fall out. Gently toss baskets every day or so to redistribute the plants, allowing for even drying and air exposure.
How to Dry Herbs in Paper Sacks and Cardboard Boxes
If you’re in a pinch and don’t have any other way to dry your plants, or if you’ve gathered plants from a friend’s garden and will be traveling for a few days before returning home, it’s possible to dry plants in paper sacks or cardboard boxes.
The key to success with this method is to avoid putting too much plant material in each sack or box, and to leave the top open so that air can flow into the container. Check plants often to make sure they are not molding or mildewing. If you notice this happening, you probably have too much plant material in the container.
Gently shake the sack or box every day or two to redistribute the plant material and assist the drying process. Plants will usually dry in one to two weeks.
Testing for Dryness
Most plants, when fully dry, will be brittle and make a snapping or crackling sound when they are crushed. When this happens, your plants are ready to store; it’s best to do so promptly to decrease their exposure to air and dust, which will degrade them more quickly.
Another way to test for dryness is to gently tear a piece of the plant material. If you notice any moisture beads forming along the tear, the plant needs to dry a bit longer. You can also place the edge of the tear against your upper lip, the most sensitive part of your body. If you feel any moisture there, let the plant dry a while longer before storing it.
Before storing herbs that are dried, crumble a piece in your hand to make sure there is no moisture in it. This will ensure that it does not mold during storage.
Proper Storage Methods
Choosing the right container or location for storage can often affect how well your plants keep their potency, color, taste, and smell. The best dried herb storage containers are clean, airtight glass jars or paper containers that can be taped closed. Plastic and metal containers (except stainless steel) are unsuitable, although unchipped porcelain enamel (also called enameled metal) ones are okay. Most glass jars, such as canning jars, come with metal lids, but these are worry-free because the lids have a nonmetal coating. If you would like to store herbs in decorative tins, line them first with a paper bag or waxed paper to create a barrier between the plants and the metal.
Keep herb storage containers out of direct light and away from extreme heat. Protect them, too, from moisture. Cabinets and pantries are good places to store herbs, but you can even set jars on open shelves, as long as they are not exposed to strong light or intense heat.
Properly dried and stored herbs will maintain their color; they should look vibrant and healthy. Their taste should be strong and their smell should resemble the scent when they were fresh. If your herbs do not meet these qualifications, discard them.
When properly stored, dried herbs will generally keep for a year. Ground and powdered herbs may have a shorter shelf life, four to six months, at which point just add them to the compost pile.
Reprinted with permission from Homegrown Herbs (Storey Publishing, 2011) by Tammi Hartung. Buy this book from our store: Homegrown Herbs.