Basil, thyme, rosemary, oregano … Gardens are teeming with fresh herbs right now. And while they are delightful in so many dishes, they are also wonderful to store for using later.
Drying is a great way to preserve fresh herbs and have them on-hand year-round for use in the kitchen and beyond. For many classic spices like oregano, rosemary and cilantro, it is easy to prepare a more flavorful, homemade version at half the cost of store-bought varieties.
“Drying involves no additional energy source, it’s not like you’re relying on a freezer to keep them frozen,” said Kathleen Savoie, extension educator at the University of Maine Cooperative Extension. “It’s truly the most simple.”
The first step is to harvest your herbs. Early morning is the best time to harvest, when essential oils are concentrated in the leaves. Cut healthy herbs, removing any sickly, dried or wilted leaves. Brush off any insects. If you rinse the herbs, pat them dry carefully afterward.
But how do you dry herbs? There are several methods to choose from.The method you choose will not only depend on the resources you have available, but the type of herbs you are looking to dry.
Air-drying works best for low-moisture herbs like marjoram, oregano, rosemary and dill, but it can also be used for herbs like basil, oregano and parsley if you have a little patience.
Gather a few branches or stalks of herbs together and tie with string or a rubber band. The smaller the bundle, the easier and faster they will dry. You may also consider covering the bundles with a brown paper bag with holes punched into it.
“You could just tie a rubber band around the herbs that you have and hang them up in a dry place and allow them to dry on their own, [or] cover them in a brown paper bag with holes punched into it to decrease dust or pet dander from landing on those,” Savoie said.
Hang the bundles or the bag by the stem end in a warm, well-ventilated area of your house, like a closet or a cabinet. Small leafed herbs like thyme, oregano and rosemary will take about a week to dry out completely. Larger leaves, like basil and parsley, can take up to 2 weeks.
“It depends on how much circulation, how dry the air is compared to how humid the air is,” Savoie said. “You want to check your air drying herbs at least weekly.”
When the herbs are ready, leaves will appear dark and will be crispy in texture. They will crumble easily as well. Remove the dry leaves from their stem, and chop large-leafed herbs before storing.
Microwave ovens can quickly dry tender herbs with higher moisture content like basil, parsley chives and mint. Savoie said that the microwave method is especially good for smaller quantities of herbs.
First, separate the leaves from stems and wash the parts you want to save. If herbs need to be rinsed, make sure all the excess water is removed. Otherwise, the herbs will cook in the microwave.
Sandwich no more than four or five stems of herbs between two paper towels and microwave 30-second intervals until the leaves crumble easily. Usually, this will take two to three minutes.
“It is so super simple,” Savoie said. “They retain a nice bright vibrant color. You don’t want to just use your eye. They retain a nice green color when microwaved. You need to pick them up and test how crumbly they are between your fingers.”
Using a dehydrator to dry herbs requires more equipment, but is a great way to do it quickly, especially higher moisture varieties like basil. Savoie said that good starter commercial dehydrator varieties should cost between $90 and $120.
“You may also need to buy some specific trays that can be used for fine herbs,” Savoie said. “You [also] want to look for the kilowatts. We have a nice one that is very efficient, it’s 1,000 kilowatts. The kilowatts certainly have an impact on the efficiency of a dehydrator.”
To dehydrate herbs, pre-heat the dehydrator with the thermostat set to 95 to 115 degrees Fahrenheit; slightly higher temperatures might be needed for humid environments. Place clean, dry herbs in a single layer on dehydrator trays for one to four hours.
Removing the herbs from the trays once they are done can be difficult. To catch dried herbs, it is best to remove them over a clean cloth or bowl.
Other methods for drying herbs
There are a few other methods for drying herbs, though they will not work as well in Maine as they will in other areas with different climates. For example: drying herbs on a rack outside in the sunlight.
“Sun drying is not recommended in Maine because of our weather patterns,” Savoie said. “We do not tend to have multiple days in a row of high heat and low humidity. We’re not Arizona. When you put things outside, they’re at higher risk for insects contaminating those sorts of things.”
Savoie also said that drying herbs in the oven is not as efficient as other methods because most ovens are not set up for low enough temperatures to properly dry.
“It’s got to be below 150 [degrees Fahrenheit]. Most home ovens don’t do that,” Savoie said. “Guidance tells people to open the oven door and fan to circulate the air, which is not super efficient. You can get that with a dehydrator or in the microwave.”
Storing dried herbs
Store dried herbs in labeled, dated, airtight containers like canning jars, plastic storage containers or freezer storage bags.
“You want to store them in a tight container that doesn’t have a lot of opportunity for air and humidity to get into it,” Savoie said. “You want to store them in a cupboard so they’re not exposed to sunlight.”
Wait to crumble the herbs fully until you are ready to use them in order to retain their flavor. Even though dried herbs will stay viable for several years, Savoie also said to make sure you use your herbs within a few months for maximum flavor.
“They lose their distinctive flavors over time,” Savoie said. “You really want to use your fresh herbs within three to six months. It’s not a food safety issue, it’s totally about flavor.”
For more information and guidance on how to dry herbs, Savoie recommended tuning into the University of Maine Cooperative Extension’s webinar about preserving herbs.