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. Let them drain on paper towels.
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.
Air drying in Minnesota is difficult because of the weather. Ideal conditions are consistent temperatures above 85 degrees F. and humidity below 60%.
To microwave small amounts, place herbs on a paper towel and cover with a second. Set control on high and dry them 1-3 minutes. Check, and if more time is needed, check every 30 seconds. Pay attention, because paper towels can catch fire if hot spots occur.
Dried herbs keep their flavor and color three months in cupboards and up to one year in refrigerators or freezers.
To oven dry, spread a layer on a shallow baking pan. The pilot light on a gas oven or the light of an electric oven (with or without minimal heat of 110 – 130 degrees F.) works. Higher temperatures cook herbs. You might use a preheated oven with the oven light on. Stir herbs periodically until thoroughly dry.
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 quarter teaspoon ground or one teaspoon crumbled dried leaves for every tablespoon of fresh chopped herbs.