Preserving Herbs: Drying Herbs and Freezing Herbs

What Is an Herb?

Herbs have been both our medicine and our food for millennia! Think of an “herb” as any aromatic plant used for food, seasoning, or medicine. Favorite herbs include 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. If you’re growing herbs, always harvest  on a sunny morning after the dew has dried, but before the full force of the midday sun. This should be after the flower buds appear but before they open. 

If you don’t grow or collect your own, you may find fresh herbs in quantity at many farmers’ markets or speciality food stores. Sometimes is just fine to buy a few ounces of the organic herb and make the product you have been waiting to make.

Which Herbs to Freeze Versus Dry

Some herbs respond best to freezing, others respond better to drying, and some can be frozen or dried! See our chart and details below.

Drying Herbs

There are many ways to dry herbs—in a basket, hang herbs, or use a dehydrator. Certainly, some herbs can be air-dried easily, such as oregano, sage, and thyme. But unless you live in a very arid climate, herbs such as basil and parsley, which have thick, succulent leaves, are better dried in a dehydrator. You may decide how far you want to go with the process. Patty Sanders, certified herbalist, explains further …

• Hanging in bunches: The old-fashioned method of tying small bunches of herbs with string and hanging them to dry in a dark, well-ventilated 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. When leaves are dry, remove them from their stems and store in an airtight jar.

Image: Fresh herbs hanging to dry. Credit: Elena Schweitzer/Shutterstock. 

• Strip and dry in hot place: 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.
   
• Dehydrate: 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. Make sure you store the herbs in an airtight container.

Photo: Drying herbs in dehydrator. Credit: Peg Boyles.

How to Freeze Herbs

Freezing is the best way to maintain the essential oils and 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. 

There’s no need to blanch herbs for freezing. Just wash all herbs in cool, running water, and pat dry before freezing.

• Freeze in layers: The most common way to freeze herbs is to 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.
• Pack in ice cubes: 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.
• 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 de-stemmed 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 in the freezer. Use herb and oil cubes directly from the freezer or thaw in the refrigerator and use immediately. NOTE: Do not leave out at room temperature because of the high risk for botulism.

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.

Credit: Anna Shepulova | Shutterstock

Herbal Vinegar

Herbal vinegars are inexpensive and easy to make. And fresh culinary herbs make the best vinegars.  My favorite to preserve in vinegar are: basil, oregano, rosemary, dill, garlic, thyme, and sage. Learn more about how to make herbal vinegars (“pickling”) as well as herbal tinctures and herbal creams/salves*.