While fresh herbs are wonderful, drying herbs is a great way to harvest your abundance of plant material when its most potent and preserve it for later use. In this guide, we'll discuss the two primary methods of drying herbs, air drying and dehydrating, and discuss when to choose one method over the other. We'll also discuss how to tell when your herbs are dry, along with other lessons learned, and how to store your herbs once you've dried them.
Why Dry Herbs?
When drying herbs, the goal is to extend the shelf life of your favorite herbs and spices while retaining as much of their medicinal compounds as possible. And when done correctly, dried herbs should look and smell the way the plants did when they were alive. This is what sets homegrown dried herbs apart from mass-produced imported herbs. You can compare how they look, taste, and smell and immediately see the difference in quality.
The process of drying herbs removes moisture from the plant material, inhibiting the growth of bacteria and mold while concentrating their essential oils, flavors, and aromas. And since all the water content is removed, dried herbs are stronger than fresh herbs and you can use a smaller quantity of them in recipes.
Air Drying Herbs
Air drying herbs is a gentle method that requires minimal equipment, and it's definitely the way to go with herbs that are more sensitive to heat. A lot of the leafy culinary herbs like basils, mints, chives, parsley, and dill are best air dried. Harvest them in the morning when their essential oils are at their peak. Then you can either bundle them together in small batches to hang upside down in a cool, dry, well-ventilated area. You can also makeshift your own screens or put the herbs on hanging racks to dry. We like these collapsible hanging racks because they're inexpensive, easy to dry a lot of herbs at once, and easy to store when not in use. Air drying herbs usually takes about 1-2 weeks, depending on the temperature and humidity.
Drying Herbs in a Food Dehydrator
Dehydrating herbs is a faster method that involves the use of specialized equipment. This method is ideal for resinous herbs with thicker leaves that can withstand slightly higher temperatures. It also works well for fruits, roots, and barks. Think calendula, ashwagandha, ginger, turmeric, horseradish, elderberries, figs, tomatoes, peppers. Another way we use our dehydrator is to finish off a batch of air dried herbs. If it's especially humid outside and will be for awhile, we'll air dry our herbs most of the way and then put them in the dehydrator on the lowest setting until they're completely dry. Just be sure to check the dehydrator often, because too much heat can fry all the herbs and zap their color, flavor, and aromatics. Trust us, we've done it. It's incredibly disheartening to harvest a beautiful batch of homegrown herbs only to turn them into a brown, lifeless pile that is best used as mulch.
Choosing a Food Dehydrator: You can probably pick up a used dehydrator for pretty cheap at a thrift store and that can be great if you're on a budget or aren't sure you'll get enough use out of it to justify a larger expense. Just know that quality varies widely. We've found that the cheap ones don't dry herbs evenly, don't have a low enough setting for herbs, and we've even had the plastic shelves turn brittle or melt. We use this Excalibur dehydrator and find it to be well worth the investment. There's also a 4-tray version if you don't think you'll need all 9 trays.
How to Tell When Your Herbs are Dried
Sometimes it can be hard to tell if your herbs are fully dried. They may seem like they're dry, but even a little bit of moisture can cause them to mold once they're sealed away in jars. The best way to tell that your herbs are fully dried is by doing a snap test. If the stem snaps easily between your fingers and the leaves crumble easily, your herbs are good to go. If not, give them more time to dry. With flowers like calendula, verbena, and red clover, it can be a bit more difficult to tell if they're completely dry. You can cut into the flowers to test the center. And if you're even just a little bit unsure, dry them longer.
Storing Your Dried Herbs
Once your herbs are fully dry, you can strip the leaves from the stems (a process called garbling). Then immediately store your dried herbs in airtight glass jars and keep them in a cool place out of direct light. It may look pretty to display your herbs on a shelf for all to see, but light, heat, and humidity are not your friends. They'll degrade the quality and potency of your herbs pretty quickly. You can also add a few food-grade silica gel packets to your jars -- especially if humidity can be difficult to control. And lastly, don't forget to label your jars! Write the name of the herb, the date you packaged it, and anything else you want to keep track of.
How Long do Dried Herbs Last?
Since there are so many factors at play here from the type of herb being harvested, the environment in which it is grown, the time it was harvested, and the way it is processed and stored, this is not an easy question to answer. However, in general, herbs that are kept whole and stored appropriately tend to retain their flavor and potency for up to two years. It is certainly safe to use your dried herbs longer than this, but their flavor and quality will diminish over time. The best way to prolong the shelf life of your dried herbs is to make sure they're stored in airtight containers in a cool, dark, dry place that is away from direct sunlight, heat, and humidity. And if you want to crush or powder your herbs, do this in small batches as needed.