Simple Strategies for Preserving Herbs

Drying herbs and flavoring vinegars and oils

Late fall is a time of big harvests in the garden, particularly our most frost-sensitive vegetable crops like squash, tomatoes, and peppers. We can be so busy bringing in the vegetables that we forget about the herbs. And although some herbs–like oregano and thyme–can withstand lower temps well into the winter months, most will need to be harvested soon. But what to do with a great big herb harvest? When processing large quantities of herbs, a quick and simple approach is often best. Read on to learn a few fuss-free methods for drying herbs and for making flavored oils and vinegars.

Drying Herbs 

Bundling herbs and hanging them from string is a time-honored approach for good reason–it works! But you’ll still need to understand a few basic principles to ensure that your herbs retain their potency and remain mold-free.

First, discourage mold by choosing a warm, dark, dry, and well-ventilated area for drying. The more quickly your herbs dry, the more they will retain both flavor and color. Find an attic, spare room, dry closet, or any low humidity area to hang your sprigs and bundles. Use baker’s twine, garden twine, or rubber bands to tie your stems, but keep the bundles to a modest size so that air can freely circulate.

An even quicker method is to use an oven. Set the oven to its lowest temperature and leave the door half open. Scatter your herbs on a parchment-lined sheet pan and place on an oven rack. Avoid overcrowding or piling plant matter; a bit of space allows moisture to escape. Check on the herbs every fifteen minutes to make sure they are not overheating.

Herbs are ready for storage when they are brittle and easily break. If they are still soft or spongy, they'll need more time to dry. Once dry, place the herbs in airtight containers stored in a dark cupboard or pantry. Check the containers in a couple of days to make sure no moisture has accumulated inside; if you see any signs of moisture, then the herbs need to be returned to their drying station. Most dried herbs will keep their flavor for up to a year.

Herb-infused Vinegars and Oils

Another easy way to preserve your herbs is to make herb-infused vinegars and oils. Use them for salad dressings, sauces, stir-fries, and marinades. If you are rinsing your herbs, use a salad spinner and/or paper towels to remove any moisture before adding the herbs to your recipe.

Herbal Oils

Both coconut and olive oil have a long shelf life and will capture flavors well. You can always use the dried herbs you have on hand to make a “bouquet garni” style oil. Because oils are anaerobic, it is safest to use the dried herb rather than fresh (the high acidity of vinegar allows for fresh herbs). Use the recipe below (adapted from Herbs for the Home by Jekka McVicar) as a springboard for your own recipe; substitute and swap out herbs according to what you have on hand. The following quantities are for the dried herb:

Bouquet Garni Oil

1 tablespoon thyme
1 tablespoon sage
1 tablespoons flat-leaf parsley
1 tablespoons oregano
1-2 dried bay leaves
A pinch of chili flakes (optional)
2 cups olive oil

Heat your oil to 180°F in a pot. Grind the dried herbs with a mortar and pestle, adding a few tablespoons of oil as you work. Add these contents to the rest of your oil and store in a clean, wide-necked jar. Make sure the herbs are covered by at least an inch of oil. Allow to cool and then cap the jar. Cover the jar and leave it in a dark place for about two weeks to infuse the oil with flavor. Every few days, shake or stir the contents of the jar. After two weeks, strain the contents through cheesecloth or a mesh strainer into a clean jar or pretty bottle; label and date. Use your oil within 3 months. You can find more about preparing herb oils safely here.

Herbal Vinegars

Flavoring vinegars with herbs is a lot like flavoring oils, and it’s fun to experiment with which vinegars pair best with which herbs. White wine, red wine, and rice wine vinegars all carry herbal flavors well; balsamic pairs well with tarragon, basil, or rosemary; and you can almost never go wrong with apple cider vinegar. The following recipe, couldn’t be simpler; start with:

10 tablespoons chopped herbs
2 cups cider or white wine vinegar 

First, chop up about 10 tablespoons of fresh herbs and pound them with a mortar and pestle. Basil, marjoram, oregano, dill, fennel, thyme, savory, tarragon, or chervil are all good choices; proportion them according to your taste. Next, heat half the vinegar on the stove (just below a simmering heat) and pour over the herbs. Allow to cool and then add this mixture to the remaining unheated vinegar and leave in a sealed jar on the windowsill for two weeks. Shake the jar every day. After two weeks, strain the contents and store in the pantry. If you really want to get fancy, add a garlic clove and a few peppercorns!

Keep experimenting with flavors and enjoy the process. Not only are home-dried herbs and herbal infusions a wonderful addition to your culinary toolbox, they make inexpensive but delightful gifts for friends and family. And nothing goes to waste!