3 Ways To Preserve Medicinal Herbs: A How-To Guide

How you preserve and store your medicinal herbs is an important part of retaining their potency and effectiveness. There are a variety of ways you can use to ensure your harvest will be potent and useful long after the growing season. Today, I will focus on three different ways to preserve your medicinal herbs: dehydrating, freeze-drying, tincturing, and oil making.

Dehydrating Herbs

Dehydrating is one of the easiest ways to preserve herbs and is effective for drying whole herbs or small pieces of plant parts. Some important things to mention when you are drying herbs…low and slow is best when dehydrating. The properties we’re after don’t respond well to high heat. If you crank the heat or put them directly in the sun, you’ll end up with scorched plant matter devoid of most, if not all, of those good herbal properties. On the other hand, if you are air-drying your herbs, you’ll only want to leave them out until they’re dry. Don’t allow them to hang too long, or they’ll end up damaged as well. The short explanation…pay attention to your herbs during the preservation process no matter which approach you use.

Using a Dehydrator: When using a dehydrator, low and slow is the best way to go. Keep the temperature of your dehydrator set between 90º-110ºF. Choose the lower temperature for leafy herbs and the higher temperature for roots, barks, berries, stems, and dense flowers. This preservation approach does take several hours, but setting the temperature higher in an attempt to dry them faster will only break down all the good properties of your herbs. My favorite dehydrator brand is Chard, as they are very affordable and efficient. Be sure to space your herbs apart some on each dehydrator tray to ensure adequate airflow.

Air Drying: Air drying is the easiest method we’ll talk about today. The downside is it does take your herbs considerably longer to completely dry, but it has the bonus of no electricity or babysitting an appliance. This traditional method works well for the aerial parts of the plant. To use this method, hang small bundles of leafy herbs upside down in a well-ventilated place, out of direct sunlight, with good air circulation. Use a rubber band to secure the bundles and a paper bag with holes to cover them. Denser plant pieces, roots, barks, and dense blossoms should not be air-dried. Air-drying these types of herbs increases the chances of them developing mold, so stick to the dehydrator for those.

Oven Drying: As I already mentioned, herbs prefer lower heat. If your oven doesn’t have a setting of 100ºF, I personally wouldn’t use this technique. Many modern appliances, however, have a dehydrator setting, which is a great option without investing in a separate dehydrator. However, the temperature and amount of ventilation are incredibly important when drying herbs, so be sure to familiarize yourself with your appliance and its capabilities before jumping into this method. If you are going to use your oven, be sure that you have set it to the lowest temperature you can (90-100ºF) 

Freeze Drying Herbs

To freeze dry is the gold standard of herb preservation. It removes the moisture from the plant yet maintains the bioactive compounds like vitamins, minerals, antioxidants, and essential oils. Because freezing and drying are both utilized in this process, the flavor, aroma, color, and texture are also retained. When stored properly, freeze drying can extend the shelf life for several more years versus dehydrating alone.

Like all freeze-dried foods, medicinal herbs should be stored in a cool, dry place away from direct sunlight. Exposure to light and heat can cause the herbs to break down and lose their potency. Storing in mason jars or mylar bags are both acceptable ways to properly store freeze-dried herbs.

Infusing Herbs

Tincturing

Tincturing is the process of preserving herbs in a high-proof alcohol. This process pulls the medicinal properties out of the herb into the alcohol, giving you a concentrated herbal preparation. Because of the use of alcohol, this type of herbal preservation can be stored for several years if prepared and stored properly.

When you are tincturing herbs, it’s best to start by making single herb tinctures vs adding multiple different herbs into one tincture bottle. Each herb has its own specific guidelines with herb-to-alcohol ratio, as well as correct dosage. For this reason, it’s a much better and safer option to stock your home apothecary with single herb tinctures, then blend them as needed. To learn how to blend tinctures, check out this workshop.

There are other types of liquid form preparations that are available, such as glycerites. However, the shelf life of these preparations is significantly lower and should not be utilized for long-term preservation.

Herbal Oils

Creating herbal oils is a fast and easy way to preserve your herbs for up to a year. Herbal oils are a good way to tap into the topical benefits many herbs have. Knowing as much about the herb you are using as possible is important here because the prep work you do before you infuse will make or break your herbal oil. Some herbs need to be dehydrated first before they can be infused into oil, to ensure the water content of the fresh herb will not compromise the potency of the preparation. Others, like St. John’s Wort, need to be fresh and should be infused fresh to tap into the amazing properties it holds. One of my favorite books to learn about herbs and the step-by-step processes needed to make potent herbal preparations is ‘The Modern Herbal Dispensatory’. It’s great for herbalists of all levels, and I seriously cannot recommend it enough.

Storing Your Herbs

Proper storage is crucial for maintaining the potency and safety of your preserved herbs. Here are some tips:

  • Airtight Containers: Store herbs in airtight containers, such as canning jars with tight-fitting lids, to prevent moisture and air from getting in. Label your herbs with their name and the date they were preserved. ALWAYS label your jars…after more than a decade of growing and preserving herbs, trust me when I say, you will NOT remember what they are.
  • Cool, Dark Place: Store your jars in a cool, dark place. Light and heat will break down herbs and affect their potency and safety.
  • Avoid Strong Smells: Be aware of what you are storing your herbs with. Strong-smelling items like garlic, onion, or cleaners can affect the smell and taste of your herbs. If you must store them together, be sure to keep them in their own jars with airtight lids.
  • Humidity Levels: If you live in an area with high humidity, consider running a dehumidifier and keeping track of the humidity levels in your storage area.
  • Regular Checks: Regularly check your herbs for signs of moisture, discoloration, and off smells. Pay close attention to denser herbs like berries, barks, roots, and dense blossoms for signs of mold or other degrading. Discard any herbs that show signs of spoilage.

The Importance of Proper Storage

It’s normal for herbs to lose some of their potency as they age; however, improper storage can compromise their quality and effectiveness, leading to a loss of potency and even toxicity. Proper storage ensures that you can enjoy the medicinal properties of your herbs for medicinal purposes, culinary uses, and in your home apothecary.

Herbs are prolific, and beyond the three methods we’ve discussed for preserving medicinal herbs, they can be used fresh, as fertilizer for other plants, and in various medicinal and topical preparations. You’ll still likely have plenty of your crop to practice these preservation techniques. Properly done, you’ll have enough preserved herbs to last you until next year’s harvest.

Remember, preserving and storing your medicinal herbs properly is a great way to ensure that you can enjoy their benefits throughout the year, whether for herbal teas, tinctures, or culinary uses. With these tips, you’ll be well on your way to maintaining a well-stocked and potent herb supply.

If you’d like to learn more about ways to preserve medicinal herbs, click the video below.