Preserving herbs by freezing or drying
Herbs are a great way to enhance your everyday meals. They can add new flavors and colors to common foods. Freezing and drying herbs when they're plentiful allows you to use them later.
Harvest, sort and wash herbs
Most herbs are at peak flavor when flower buds first appear, before they are fully open.
- Pick herbs in the morning, just after the dew evaporates and before the sun is hot.
- Discard bruised, soiled or imperfect leaves and stems.
- With the leaves on the stems, lightly wash in cool running water.
- Gently shake to remove excess water.
- Drain on paper towels.
Frozen herbs can work for cooking, though they are usually not suitable for garnish as they become limp when thawed.
Options for freezing herbs
- Place a few sprigs or leaves in freezer wrap or in an airtight freezer container.
- Spread on a tray or cookie sheet and place in the freezer. When frozen solid, pack into airtight containers.
- To use in soups or stew, dice washed herbs and pack into ice cube trays. Fill the spaces with water. When frozen, pop out cubes and store in airtight containers.
For cooked dishes, use the same amount of frozen herbs as you would fresh ones.
The time it takes in ovens or food dehydrators varies with the herb and appliance used. Herbs are dry when leaves crumble off the stem. Don’t crush leaves until using them – they’ll lose their flavor more quickly.
Air drying in Minnesota is difficult because of the weather. Ideal conditions are consistent temperatures above 85 F and humidity below 60 percent.
Using a food dehydrator
Dry herbs in the dehydrator between 95 and 110 F. Place stems on drying trays so they do not touch. Larger leaves can be dried separately.
Using a microwave
Parsley, basil and celery leaves dry well in some microwave ovens with a wattage rating of 1,000 or less. Place herbs in a single layer on a paper towel and cover with a second paper towel. Microwave on high and dry for 2 to 3 minutes per cup. Check every 30 seconds, rotating the herbs. Continue checking every 30 seconds until dry. Check, and if more time is needed, pay attention, because paper towels can catch fire if hot spots occur.
Using an oven
To oven dry, spread a layer on a shallow baking pan. Use the lowest temperature possible, not above 180 F. Higher temperatures cook herbs. Prop the oven door open. Dry for 3 to 4 hours. Stir herbs periodically until thoroughly dry.
Stems of herbs such as mint, sage or thyme can be tied in a small cluster and hung in a dry area with good air circulation. Tie stems together with a rubber band into a cluster. Hang herbs away from the sink, stove or dishwasher where there is a lot of moisture.
Keep dust off herbs by covering them with a paper bag punched with holes. The holes will allow air to circulate. If drying seedy herbs, place them in the bag so that the bag can catch the falling seeds. To destroy any insects or insect eggs, heat the herbs or seeds at 160 F for 30 minutes or freeze at 0 F or lower at least 48 hours.
Testing for doneness
Herbs are sufficiently dry when leaves are crispy and crumble easily between the fingers.
Store in airtight containers
Place them in airtight containers or jars with tight-fitting lids. Glass keeps aromas in. Herbs must be completely dry or they mold. Store in a cool, dry, dark area, away from light and heat. Dried herbs keep their flavor and color three months in cupboards and up to one year in refrigerators or freezers. To substitute dried herbs, use a generous 1/4 teaspoon ground or 1 teaspoon crumbled dried leaves for every 1 tablespoon of fresh chopped herbs.
Reviewed in 2018