Although I grow many herbs fresh in pots and in my greenhouse for year-round use, I also like to preserve an abundant supply for the long season when nothing grows outdoors. It’s fun and not all that time-consuming.
I think of an “herb” as any aromatic plant used for food, seasoning, or medicine. I’m thinking Greek oregano, basil, rosemary, thyme, dill, parsley, and the various mints, as well as the medicinals: yarrow (leaves and flowers), elderberry flowers, plantain, comfrey, heal-all, and others.
The volatile oils and medicinal phytocompounds are most highly concentrated in leafy herbs as the flower buds swell but haven’t yet opened. Whenever possible, I harvest mine on a sunny morning after the dew has dried, but before the full force of the midday sun.
If you don’t grow or collect your own, you may find fresh herbs in quantity at many farmers’ markets or speciality food stores.
Depending on the intended use, home gardeners have several ways to preserve herbs for cooking and medicine.
The old-fashioned method of tying small bunches of herbs with string and hanging them to dry in a warm, dark place still works well for most leafy herbs and flowers. Rinse the herbs well under cool running water, lay them to wilt and dry in the sun, then tie them up.
To dry a large harvest of tea and medicinal herbs, I’ve had success with stripping individual leaves or flower clusters from their stems, spreading them one layer deep on a thin cotton sheet and tacking the four corners to boards in the steeply pointed ceiling in my attic. It’s hot, dry and dark up there in summer, and the herbs dry quickly. When they crumble easily, I sweep them into a clean pillow case or heavy paper bag and crush them, then store in glass jars in a dry, dark place.
A few years ago I bought an eight-tray electric food dehydrator to try drying tomatoes, zucchini, and garden fruits. I’ve found it especially useful for drying aromatic culinary and tea herbs: oregano, sage, basil, mint. Because it removes moisture at such a low temperature (about 95°) with continuous airflow across the drying racks, it preserves the rich flavors of these culinary herbs better than oven or air-drying.
When the herbs crumble easily, I sweep them into a large paper bag, crumble them with my hands, and funnel them into glass containers. I like small-mouthed mason jars for storage because they accept the lids from grated parmesan-cheese containers that let me shake herbs right from the jar.
Freezing is the best way to maintain the spritely flavors of delicate herbs such as dill, fennel, thyme, basil, and chives (although you can freeze any herb). You have several options for freezing.
- Chop the well-rinsed herbs (create a mixture if you like), pack them tightly into ice-cube trays, add just enough water to cover, and freeze. You can remove the herb cubes from the trays and store them in a freezer bag or rigid container.
- Lay sprigs of rinsed herbs one layer deep in a freezer bag and freeze flat. This method allows you to reach into a bag, remove the needed amount of herbs, and crumble them quickly into a salad dressing, soup, or other dish.
- Make “herbsicles.” Without chopping, pack a handful of fresh leafy herbs in a small plastic snack bag That’s labelled with the herb(s) inside. Roll tightly, seal, then secure with a couple of rubber bands to hold the cylindrical shape. Pack three or four of these frozen logs into a zippered freezer bag. When you want to use one, remove the log from the bag, slice off what you need from one end, and quickly return the log to the freezer.
- Freeze in olive oil This method makes a perfect way to prepare herbs and herb mixtures for salad dressings, soups, and other prepared dishes. Just blend the desired herbs with enough oil to make a pourable mixture, pour into ice cube trays and freeze. If you love basil (or any other herb) pesto, puree your big bunches of destemmed basil with olive oil and freeze in ice cube trays. Run the trays under hot water to remove the cubes, pop them into freezer containers or wrap individually in plastic wrap, and store.
- Of course, the ice-cube method is a perfect way to preserve your pesto, too. A couple of basil-and-garlic pesto cubes will improve the flavor of just about any winter soup.
*Note: Please reserve herb-infused oils to make products for external use only, in creams, salves, lip balms, and/or lotions. Although it’s safe to consume an oil infusion that’s a day or two old (refrigerate after you make it), clostridium botulinum, the bacterium that causes botulism poisoning, can thrive and concentrate in a fresh-herb- or garlic-infused oil intended for dipping or salad dressings, even if it’s been refrigerated.
The commercial oil infusions you find in grocery stores and specialty food markets have been processed with techniques and equipment not available in home kitchens.