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Preserving herbs by freezing or drying

Close-up of oregano plant.

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.

Preserving herbs

Freezing herbs

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.

Putting herbs in a white ice cube tray.
Dice washed herbs and pack into ice cube trays
Adding water to herbs in a white ice cube tray.
Fill the spaces with water
Frozen herbs ice cubes.
When frozen, pop out cubes and store in airtight containers

Drying herbs

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.

Drying oregano in a dehydrator.
Drying oregano in a food dehydrator

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

Dehydrator drying is a fast and easy way to dry high quality herbs. Set the thermostat to 95 to 115 degrees F. Place washed herbs in a single layer on dehydrator trays. Drying time varies from 1 – 4 hours. Check your dehydrator instruction booklet for exact temperature and drying times. Check often until leaves crumble and stems break when bent.

Using a microwave

Drying herbs in the microwave.
Drying herbs in the microwave

Parsley, basil and celery leaves dry well in some microwave ovens with a wattage rating of 1,000 or less for 2-3 minutes. Place herbs in a single layer on a paper towel and cover with a second paper towel. Check every 30 seconds, rotating the herbs. Continue checking every 30 seconds until dry. Remove herbs that are dry and brittle to prevent hot spots causing the paper towel to catch fire. Continue drying for 30-second intervals until all pieces are dry and brittle.

Dried herbs keep their flavor and color 3 months in cupboards and up to 1 year in refrigerators or freezers.

Oven drying

Oven drying is especially good for mint, sage or bay leaf. Remove the leaves and dry individually instead of drying whole stems. Spread washed leaves in a single layer on a shallow baking pan. Dry at temperatures of 110 – 130 degrees F. The pilot light on a gas oven or the oven light in an electric oven is enough heat for overnight drying. Dry for 3 to 4 hours.  Stir herbs periodically until thoroughly dry.

Indoor air-drying

Indoor air or room drying is an option for sturdy herbs like rosemary, sage, thyme and parsley. 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.

Herbs hanging upside down from string, drying.
Herbs hanging upside down for drying

For tender herbs like basil, oregano, tarragon and mint with high moisture content, put herbs in a paper bag with stems sticking out of the bag. Close opening with a string. Tear or punch holes in the sides to allow air to circulate. Herbs are dry when leaves crumble and stems break.

Herbs take 1-2 weeks to air dry at room temperature. 

When drying is complete and to destroy any insects or insect eggs, heat the herbs or seeds at 160 F for 30 minutes or 175 F for 15 minutes or freeze at 0 F or lower at least 48 hours.

Vine Drying

Vine drying is a type of sun drying and works well for coriander, dill, caraway, mustard, and fennel. Simply leave it on the vine in the garden. When the vines, leaves, stems or seeds are dry and shriveled, harvest them and remove them from the stem. If still moist, the drying process is not complete and it will mold. Complete the drying process in the oven, dehydrator or air dry in a room. Find details on vine drying at the National Center for Home Food Preservation.

For any outdoor dried products, it is important to kill any insects and/or their eggs through a  pasteurization process. There are two ways to pasteurize either by freezing or heating. To pasteurize by freezing, seal food in freezer bags or containers and place in a freezer set at 0°F or below for at least 48 hours. To pasteurize by heat, place food in a single layer on a cookie sheet and put into an oven preheated to 160°F for 30 minutes or 175°F for 15 minutes.

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.

Marilyn Herman and Suzanne Driessen, Extension educator

Reviewed in 2021

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