When herb growing season draws to a close – or you have more fresh herbs on hand than you can use – plan ahead and preserve your harvest for future use. Next winter, the fresh taste of homegrown basil in your pesto or pasta sauce will be a welcome reminder of your summer garden.
With proper preparation and storage, herbs can be kept for up to a year. Most herb flavor will begin to diminish after that time. Airtight glass storage containers are preferred, but herbs can also be stored in the freezer in plastic containers. Be sure to discard herbs if they begin to mold.
After picking, wash in cold water and dry herbs thoroughly to remove any dirt or impurities. A salad spinner works well, or simply wash by hand and dry by pressing herbs gently with a towel to absorb the extra water.
For leafy herbs, including basil, chives, dill, mint and parsley, strip the leaves from the stems or stalks, then roughly chop prior to drying. Herbs with woody stems, such as rosemary or thyme, can be left intact. Remove any flower blossoms prior to drying.
Short Term Storage
Herbs can be stored fresh in the refrigerator for up to a week. Wrap the stems in a damp paper towel, and place inside a plastic bag with a few holes punch into it for air circulation.
Herbs can be naturally air dried, or also dehydrated in a microwave or oven. Herbs need to be dried quickly and thoroughly in order to prevent mold growth. When sufficiently dry, herbs should feel dry and crumbly to the touch.
To air dry, spread leafy herbs out on a screen that is elevated to allow air circulation on the top and bottom. Turn herbs often to dry evenly. To air dry herbs with woody stems, bundle stems in bunches then hang them upside down in a darkened room with good air circulation. The drying process will take about a week, and the inverted position will allow the plant's flavorful oils to concentrate in the leaves. Leaves can be stripped from the woody stems when dried.
To dry herbs in the microwave, spread herbs in a single layer on a paper towel, and microwave for 1-2 minutes on high power. Drying times may vary, so monitor your herbs to make sure they're completely dry.
To dry herbs in the oven, spread herbs in a single layer on a cookie sheet and place in a low heat (150°F- 175°F) oven for 2-4 hours.
Many varieties of herbs can be harvested and then frozen for storage. One of the easiest preservation methods, freezing preserves herb flavor, but not color and appearance. Frozen herbs are great for use when cooking, but won't look fresh enough to use in salads or as a garnish.
For leafy herbs, spread loosely on a cookie sheet, then place in the freezer. After herbs have frozen, transfer them to an airtight plastic bag or similar container and return to the freezer.
To freeze herbs with woody stems, place in an airtight plastic bag and then freeze. After a few weeks, remove the bag from the freezer. Use your hands to strip the leaves the leaves from the stem. Store in an airtight container in the freezer.
Frozen herbs do not need to be defrosted before use – just go ahead and add them to your stock, stew or sauce straight from the freezer.