Preserving Your Home-Grown Herbs

Preserving Your Home-Grown Herbs

Posted by Kerry Kelley on Oct 1st 2022

Fall brings many changes to the garden. Some are particularly lovely, like the warm glow of the autumn sun highlighting nature’s new palette of ruby, copper and gold. Some are beneficial such as the bit of frost that sweetens persimmons and root crops. Some are just plain annoying—does anyone like raking leaves?

Watching all those annual flowers fade away is always sad. We may miss our zinnias, and lament the passing of our petunias, but this gives us a chance to reimagine and reinvent our plantings come spring.  Flowers come and flowers go, that’s all in a year’s gardening. But how are we supposed to live without our basil for 6 months? THAT is the worst of fall’s effects—turning a lush, mouth-watering mound of green into a slimy, blackened mass of mush.

There’s nothing like fresh herbs to perk up everyday recipes, and nothing like the satisfaction and assurance of growing your own. So take heart--there’s no reason to let all that tasty goodness perish. It’s not difficult to preserve your herbal delights for a winter-long supply of flavor. You might even be able to create some amazing home-made gifts while you’re at it!

General Harvesting Tips:

  • Gather early in the morning when the concentration of oils in the leaves are highest.
  • Keep plants deadheaded unless you are using the flowers or seeds. This will keep more flavor in the leaves and keep annual herbs from going to seed, thus ending their life cycle.
  • You can use the seed of cilantro (coriander) and dill—these often go to seed quickly in warm climates. Clip off the heads once browned and seeds are mature. Store hanging upside down in a paper bag until seeds drop.
  • Other than annuals at the end of the season, never remove more than 2/3 of the volume of the plant at any one time, 1/3 to is preferable for slower growing types.
  • Herbs should be rinsed but surface water needs to dry thoroughly before any preservation method is undertaken. Separate stems and sandwich gently between two layers of paper towels or dishcloths for faster drying.

Preserving Methods/Projects:

  • Drying: several methods; best for herbs with thick, narrow leaves, furry leaves; most perennial herbs: oregano, rosemary, thyme, winter savory, etc.They can be allowed to dry naturally or with the aid of oven, microwave, or dehydrator. To air dry herbs without too much fading they should be placed in a dry, dark place such as an attic or shed. To prevent mold, leaves must be completely dry before storing, preferably in a dark glass, well-sealing container. This may take one to three weeks depending on the temperature, humidity, and type of leaf. The faster they dry the more flavor and color they will retain. To maximize flavor leaves should not be crushed until ready to use.
  • Line dried herbs should be in bundles no more than 1 inch thick. Stems can be secured with twine, rubber band, or florist wire, and can be attached to the line with paper clips, clothespins, or with the ”tail” of the wire. To keep out dust fold large paper in half and hang over the line—old wrapping or shipping paper or cut open grocery bags work well. Alternatively, each bundle can be placed foliage end down in a paper lunch bag, securing around the stems at the top (this also works well for seed heads you want to save as the seed will drop into the bag). No matter what type of paper, flaps 1” wide and ½ inch deep should be cut at intervals on both sides to provide needed air flow while keeping dust away. If hanging is not an option then herbs can be spread in a thin layer in cardboard box lids. These can be stacked in alternate directions to save space and keep out dust. A covering of cheesecloth might be beneficial in very dusty spots.
  • Oven drying takes much less time, about 1 to 4 hours, and preserves more flavor and color. Spread rinsed herb leaves in a single layer on cookie sheets and place in the oven at the lowest setting (usually 170 to 180 degrees). Check every 1/2 hour, turning when dry on one side. When completely dry and cooled, transfer to spice jars or Ziploc bags. Do not crush until ready to use as this will release the flavor you're trying to save. Stored cool, dry, and dark these can last up to 2 years.
  • Microwaving can be a bit trickier, so don't use all your harvest in one go. Remove any thick stems and place the herbs one kind at a time in a thin layer between two paper towels. Start on high for 30 seconds to one minute, and then in 15-30 second increments until completely dry. Something with thicker more resinous leaves like rosemary will be safer with longer increments than one with leaves as delicate as dill. Everyone's microwave is different, so experiment until you find the sweet spot for that particular herb. Storage is the same.
  • Dehydrator--awesome if you have one! Storage the same as above.

Freezing: several methods; best for herbs with softer leaves like basil, dill, cilantro that lose flavor when dried, but almost any herb can be frozen. Just remember that they will be limp once defrosted, so won't be suitable for garnishes, and if you will want to use them chopped it's best to do so before freezing. You can freeze whole herb stems, or freeze chopped herbs in water or oil. To freeze whole stems or leaves, rinse and dry herbs and place in a single layer spaced on a cookie sheet, then put in the freezer for a few hours. Frozen leaves and stems can be stored in a well-sealing container or Ziploc bag and taken out as needed. As odors can transfer through plastic in the freezer, strong smelling herbs may need to be wrapped in foil or placed in glass containers. If your basil turns black when freezing then usually it is due to surface water on the leaves, so make sure herbs are dry first. Chopped herbs can be placed in ice cube trays and covered with water or oil. It's a good idea to measure the amount first and make them all the same so you'll know what you're adding to your recipe--1 tablespoon is a good amount. Push the herbs down into the compartments and add liquid until just covered, then freeze. If using water the herbs will float a bit, so leave room to top up with water and refreeze so that the herbs are completely covered. You can also process the herbs in a blender using 1/4 cup oil to 1 cup herbs, then spooning the mixture into the ice cube trays and freezing. Once the cubes are frozen they can be stored in Ziploc bags, plastic, or glass containers. To use, simply drop the cubes into sauces, stews, soups, etc. If you've used water you can defrost first so the water does not dilute your recipe.

Vinegars/Oils: vinegar often used for tarragon; oils for herb mixtures. Can be tinted by adding edible flowers; storage time generally more limited. Basically, the herbs are covered with oil or vinegar and left to steep for about 3 weeks. Using a wide mouth glass jar, add the desired herbs and cover with vinegar or oil. If using vinegar you must cover the top of the jar with parchment paper or plastic first to prevent a reaction between the vinegar and the metal lid. Store in a cool dark place for 2 to 3 weeks. If not strong enough you can let sit up to 4 weeks total. Or, you can remove the first batch of herbs and add more fresh herbs and let sit again. If you prefer a faster process, the vinegar or oil can be heated unit barely simmering, then adding herbs and infusing for about 15 minutes off the heat, then strain and pour into a glass jar. Do not use unenameled cast iron or aluminum cookware. The Penn State Extension Service also recommends oil preservation should include acidifying the herbs first with a citric acid solution to prevent the growth of bacteria. Click HERE to read their instructions, "How to Safely Make Infused Oils." This is not necessary with vinegar, as of course the vinegar is acidic. You can add a fresh or dried stem or flower or two to the finished vinegar for presentation, but do not add to finished oils. All vinegars and oils are best stored in the refrigerator and used within 3 months, or they can be frozen. Cider vinegar and rice wine vinegar mix well with most herbs. Red wine vinegar and balsamic are better suited to stronger herbs like rosemary, basil, oregano and winter savory. Extra virgin olive oil or canola oil works well for most herbs.

Salting: best for savory dishes: oregano, basil, thyme, rosemary, or specific mixes like Italian or Herbs de Provence. Any type of salt may be used except iodized. Simply make alternating layers of salt and whole herb leaves in a jar and seal tightly. The first and last layer of salt should be 1/4", the interspersed layers should be just enough to cover the leaves. Store in refrigerator for up to 1 year--flavor best within 6 months. To use, crumble whole leaves and add the flavored salt instead of plain salt in your dish. Particularly nice with large grain salt as a rub to create an extra flavorful crust on meat. Don't forget to cut back on the salt in your recipe if you plan to use the infused salt! You can also mix the fresh herbs and salt in a blender or food processor, using a ratio of 3 cups of herbs to 1/2 cup salt. Do not over-process--you want a coarse mixture, not a paste. For larger/tougher leaves you may want to chop them first. Store as described previously for layering. Cut a colorful piece of fabric with pinking shears, place over the lid and secure with a rubber band, add a bow for a nice hostess gift. Don't forget to add a label for the type of herb or mixture. 

Herb Sugar: best for sweet dishes and baked goods: scented geraniums, lemon verbena, pineapple sage, lavender. Any type of sugar may be used, but be absolutely sure the herbs are dry (as in leaving overnight on a paper towel after rinsing) before adding. Use either method as for salting, above. The herb leaves should be omitted when cooking or ground finely. The most common use is to flavor sugar with rose scented geranium leaves to use in poundcake, as the flavor is hard to come by otherwise. Flavored powdered sugar can be used for dusting or in icing. Flavored granulated sugar can be used instead of regular sugar in cakes, cookies, muffins, crumb toppings, custards, etc. Lemon verbena or mint flavored sugar is nice in teas. Note if using lavender not to add too much as it can result in a "soapy" taste.

Herb Butters: Any mixture of herbs you prefer. Can be frozen in decorative molds for a nice presentation or for gift giving. Allow butter to soften just enough so it can be mixed. Leave butter to soften until just able to mash, then simply mix the herbs well into the butter. Make sure your herbs are minced or chopped to release the oils (the flavor) in the leaves. You can also use a food processor if you prefer. Add roughly 2 tablespoons of herbs for every stick (1/2 cup) of butter. For a more spreadable consistency you can add a tablespoon or two of olive oil and blend well. You can also add garlic or shallots, lemon zest or orange zest, and dried herbs or spices. Just be careful about adding anything with much water content—it will make it difficult to blend and won’t store as well or as long. Once blended, roll into a log and wrap in parchment paper and seal in a Ziploc bag, or place in any very well-sealing container. The butter can be kept in the fridge or frozen for longer term storage. For a gift presentation you can wrap the butter logs in pretty fabric and tie bows on the ends. If you want to get all Martha Stewart about it, silicone molds used for candy or soap can also be used to shape your butter into stars, bells, flowers, turkeys, etc. Fill the molds carefully, tapping out any air and pushing the butter down firmly—placing parchment paper over the mold can help. Once properly filled place in a Ziploc bag (to avoid absorbing any odors/flavors) and freeze (about 3 hours). Once frozen solid you can pop them out of the molds and store right in the bags. Let soften slightly before use—time will depend on the size of the mold and the temperature of your kitchen or dining area. You want the shape to hold up but obviously need to be able to cut or spread. Amazing on baked potatoes, vegetables, and oh, wow on a beautifully seared steak. Using unsalted butter adds needed flavor for folks on low sodium diets. Fake butter or margarine could be used if dietary restrictions require.

Wreaths/Candle Rings (faux flame recommended!): Nice indoor accent if you have a bumper crop of herbs that dry attractively, such as santolina, rosemary, lavender, tarragon, bay, or perennials such as artemesia or yarrow, or those with interesting seed heads. The easiest way I’ve found to create these is to use a grapevine wreath, available at your local craft store. Simply push thick stemmed herbs into the wreath where desired and tug gently to be sure they’re tight enough. For thinner stemmed plants make bundles about ¼’ thick at the bottom and attach to a wired florist pick, available at that same craft store. They come in different sizes—I use 3” for smaller wreaths and 5” for larger ones. The bundles can be of one herb or mixed as you like but should be roughly the same length. Then push the pick into the wreath until hidden. Continue to add stems or bundles, orienting them all in the same direction. Cut off any excess sticks or stems that protrude from the back of the wreath so it will lay flat on the wall. The nice thing about the grapevine wreath is that you don’t have to completely cover it to have a finished look, so if you don’t have a lot of herbs it will still be pretty. You can space 3 bundles evenly around the wreath, or 2 bundles and a bow, or whatever you like. To soften the look you can poke in some preserved moss, like our Oregon Green Moss. You can add accents of almost anything in your garden—heuchera leaves, grass inflorescences, and acorns still in their caps (wire these to a pick) are a few favorites.