How to Dry Fresh Herbs at Home, Air, Dehydrator, or Microwave

Drying is the easiest way to preserve herbs, according to the National Center for Home Food Preservation (NCHFP): expose the leaves, flowers, or seeds to warm, dry air until the moisture evaporates. The method has to match the herb, though, since sturdy herbs hang-dry well and tender ones mold. The steps below follow NCHFP and Oregon State University (OSU) Extension.

1. When and how to cut

Both NCHFP and OSU say the best time to harvest most herbs for drying is just before the flowers first open, the "bursting bud" stage. Pick in the early morning after the dew has evaporated to minimize wilting.

Handling tips from both sources:

• Avoid bruising the leaves.
• Do not leave cut herbs lying in the sun or unattended.
• Rinse in cool water and gently shake off excess moisture.
• Discard bruised, soiled, or imperfect leaves and stems.

OSU adds a practical step: label each bunch when you pick it, because many herbs look alike once dried.

2. Keep the heat low

OSU's general rule is that temperature should stay low, because high temperatures cause flavor loss. Both sources say sun drying is not recommended, since it hurts color and flavor.

3. Method 1: Air drying, matched to the herb

Sturdy herbs. NCHFP and OSU name rosemary, sage, thyme, summer savory, and parsley as the easiest to dry without a dehydrator (OSU adds cilantro). Tie them in small bundles and hang them. Air drying outdoors is possible, but both say indoor drying usually keeps better color and flavor.

Tender-leaf herbs. Basil, oregano, tarragon, lemon balm, and the mints have high moisture content and, NCHFP warns, will mold if not dried quickly. For these, use the paper bag method:

1. Tie a small bunch. Large bunches mold.
2. Hang it inside a paper bag with holes torn or cut in the sides (OSU says top and sides).
3. Close the top around the stems with a rubber band.
4. Hang it where air circulates. Leaves and seeds that fall off are caught in the bag.

OSU suggests warm spots with air movement, such as an attic or kitchen.

Flat drying for individual leaves. For mint, sage, or bay, both sources describe drying leaves off the stem. Lay them on a paper towel without letting them touch. NCHFP says you can layer towel, leaves, towel, up to five layers at a time. OSU says air-drying on paper towels usually takes 5 to 10 days and keeps leaves flat with good color.

NCHFP also describes a very cool oven option for these layered leaves: the oven light of an electric range or the pilot light of a gas range provides enough heat for overnight drying.

4. Method 2: Dehydrator

Both sources call this fast and easy because temperature and air circulation can be controlled. Their settings:

• Preheat to 95°F to 115°F.
• In humid areas, up to 125°F may be needed.
• Spread herbs in a single layer.
• Drying takes about 1 to 4 hours. Check periodically.

5. Method 3: Microwave, for small amounts

NCHFP says microwave drying is fast for small quantities and to follow your oven's directions. OSU gives more detail:

• Never dry more than 1 to 2 cups at a time.
• Use a single layer between two sheets of plain white paper towels. OSU warns not to use towels made from recycled paper, which can contain bits of metal that may arc and catch fire.
• As a general guide for 1 cup of herbs, microwave on high for 1 to 2 minutes, stirring every 30 seconds after the first minute, until almost dry, then let them finish at room temperature.
• OSU lists parsley, celery leaves, chives, thyme, and sage as herbs commonly dried this way.

Check often rather than running one long cycle, since OSU's general rule is that high heat costs flavor.

6. How to tell they are done

NCHFP and OSU agree: herbs are dry when the leaves crumble easily between your fingers and the stems are brittle and break when bent. Remove husks from seeds by rubbing them between your hands and blowing away the chaff.

7. Storing for the best flavor

• Pack dried herbs in airtight containers and store them in a cool, dry, dark place. OSU says they can also be kept in airtight containers in the freezer.
• Keep leaves whole until you use them. OSU explains that crushing or grinding breaks the cell walls that hold the flavor oils, so whole leaves and seeds last longest and ground herbs the shortest.
• Use within six months to one year, OSU says, for best flavor.

8. Swapping dried for fresh

Dried herbs are concentrated. NCHFP and OSU say they are usually 3 to 4 times stronger than fresh, so use 1/4 to 1/3 of the fresh amount a recipe calls for. OSU also offers an equivalence: 1 tablespoon chopped fresh herb equals 1 teaspoon dried herb equals 1/4 teaspoon powdered herb.

9. Key takeaways

• Cut herbs for drying just before they flower, in the morning after the dew dries, and label each bunch.
• Hang sturdy herbs like rosemary, sage, and thyme in small bundles; dry tender herbs like basil and mint quickly in a vented paper bag or flat on towels.
• A dehydrator at 95°F to 115°F dries herbs in about 1 to 4 hours.
• Microwave only 1 to 2 cups at a time between plain white paper towels.
• Store whole leaves airtight in a cool, dark place, use within a year, and substitute 1/4 to 1/3 of the fresh amount.