Harvesting and Preserving Herbs and Spices for Use in Cooking
The method used for harvesting herbs and spices is dependent on the plant part desired. Separate facts sheets have been written on each commonly used herb with detailed descriptions of the plant part used as well instructions for their use in a recipe. Also refer to Herb History for definitions of herbs and spices and additional historical information.
Tools for harvesting can include hand pruners, a sharp knife, or scissors. Your hands will also work well in pinching off leaves, seeds, or fruits.
Leaves should be free of insect damage and other blemishes and harvested just after the dew has evaporated from the plant in the morning. Leaves are at their peak flavor anytime before flowering and develop "off " flavors after flowering.
If harvesting the entire plant, wait until just before the flower buds open. If the plant is an annual (see fact sheet on Nomenclature for more information on plant life cycles), cut it off at the soil line. If it is perennial, cut off no more that one third of the stems.
Seeds and fruits should be harvested after they reach maturity and on a dry day. For most plants, this is when the fruit has changed from green to tan, brown, or black.
Rinsing and Storing
After harvesting, leaves and whole plants should be rinsed in cold water and patted dry. Herbs and/or spices intended for refrigerating, freezing, or drying should be preserved as soon as possible for the best flavor and color.
When storing, remember to label the container with the name of the herb or spice and the date harvested.
After rinsing, place herbs loosely in a plastic bag, and place the bag in a refrigerator. The herbs will remain fresh for a few days to a week. Another method is to place whole plants or sprigs in a jar or cup with about 1 inch of water, cover the herbs with a plastic bag and place in a refrigerator. If the water is changed daily, herbs can last up to two weeks using this method.
Basil (Ocimum basilicum) and oregano (Origanum spp.) should be used on the day harvested because they will not hold well in the refrigerator. Fennel stalks (Foeniculum vulgare) dry out quickly and should be used within 3 to 4 days of harvest.
After rinsing, gardeners have the option of freezing sprigs, whole leaves, or leaves cut or torn into smaller sections. Herbs can simply be placed in freezer containers or bags and placed in a freezer.
Alternatively, herbs can be placed in a single layer on a cookie sheet and then frozen. Once the herbs are frozen they can be placed in freezer containers or bags. This method prevents the herbs from freezing in clumps, and it may be easier to remove individual quantities for cooking.
In general, blanching herbs before freezing will sacrifice flavor but retain better color. If one opts to blanch, place the herbs in a colander and pour boiling water over them for about one second. Basil is one herb that should always be blanched. It will blacken if not blanched prior to freezing. Once frozen, herbs can last for six months to a year. Generally, herbs will retain their flavor though some will change slightly.
Frozen herbs can be used in cooking without defrosting. When using frozen herbs in uncooked foods, they should be thawed and excess water may need to be drained prior to adding to the foods. In this case, the texture may be softer than when freshly harvested.
Drying Herbs and Spices
Dried herbs and spices can last up to a year when stored in a cool, dry location. Be sure the herb or spice is completely dried prior to storing. Otherwise, they can mold and deteriorate quickly.
When drying, the flavor of strong flavored herbs, such as rosemary (Rosmarinus officinalis) and sage (Salvia officinalis), will affect the flavor of other herbs, so dry strong flavored herbs away from other herbs.
Oven-drying is a quick method to remove water from herbs and spices; however, during the drying process essential oils are lost and therefore some flavor is lost. If using this method, position herbs or spices in a single layer on a cookie sheet, and place them in an oven set at its lowest temperature. The oven door should be left slightly ajar for air circulation. Turn the herbs or spices over periodically to promote uniform drying. They are sufficiently dry when they are crisp and break easily. Avoid over-drying, and cool prior to storage.
Microwaving also removes water from the herb or spice quickly without affecting flavor. Place the herbs or spices in a single layer between paper towels. Microwave for up to 4 minutes, turning them over and checking for doneness every 30 seconds. The paper towels need to be replaced once they are too moist. The herbs are sufficiently dry when they are crisp and break easily. Again, avoid over-drying, and cool prior to storage.
Air-drying is another method to preserve herbs and spices. One method of air-drying entails tying a string to the base of a bundle of whole plants, sprigs, or seed heads. Make sure the bundle is small enough for adequate air circulation and uniform drying. Then hang the bundle upside down in a warm (68 to 90°F), well ventilated, dry and dark place.
The herbs or spices are placed in the dark because essential oils break down in sunlight. A paper bag can be placed over the herbs or spices to keep them out of the light, to catch pieces that may fall, and to keep them free of dust.
Alternatively, leaves, seeds, and fruits can be placed loosely in a single layer on a wire screen, slatted tray, or muslin for drying. They will need to be turned over periodically for even drying. Air-drying can take two weeks or more. As with other drying methods, the herbs and spices are sufficiently dry when they are crisp and easily broken.
- Billingsley, G. (Ed). 1997. The Packer 1997 Produce Availability & Merchandising Guide. Vance Publishing Corp., Lenexa, KS.
- Bown, D. 2001. The Herb Society of America New Encyclopedia of Herbs and their Uses. DK, London.
- Bremness, L. (Ed). 1990. RD Home Handbooks Herbs. The Reader's Digest Association, Inc., Pleasantville, NY.
- Buchanan, R. (Ed). 1995. Taylor's Guide to Herbs. Houghton Mifflin Co., Boston.
- Kowalchik, C. and Hylton, W.H. (Eds.) 1987. Rodale's Illustrated Encyclopedia of Herbs. Rodale Press, Emmaus, PA.
Prepared by Elsa S. Sánchez, assistant professor of horticultural systems management and Kathleen M. Kelley, assistant professor of consumer horticulture.
TitleHarvesting and Preserving Herbs and Spices for Use in Cooking
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