Not all herbs should be harvested in the same fashion. For more detailed instructions consult the article on each specific herb.
In general, harvest annual herbs just before or in early bloom.
Harvest herbs in the morning after the morning dew has dried from the herb plant.
It is best to always leave 30% of the herb in the garden except for the final harvest before winter.
Rinse the fresh harvested herbs in fresh water and before they wilt. Gently blot the herbs dry with a cloth or paper towel.
Proceed with your chosen method of herb drying.
Be patient! If you are in a hurry or have a high volume of herbs to dry, consider using a Food Dehydrator as the Herb Dryer. Always be aware that when drying herbs, the intent is to use warm, not hot, and dry air to draw moisture from the surface of the herb leaf through evaporation. A temperature over 100-105 degrees will begin to degrade both the color and taste of your herbs.
Herbs must be dried thoroughly before storing. If you want the best from your efforts, so BE PATIENT!!
The intent is to simply dry your herbs, not cook them. When at all possible, use moving, warm, dry air away from direct light. The only sure way to do this is in a controlled environment such as that which is on the inside of a food dehydrator!
Many references suggest oven drying. In limited cases it may be possible, but be careful! Temperatures above 90-110 degrees will progressively degrade flavor, aroma and the color of your hard-earned harvest. Why do we grow herbs: To enjoy the flavor and aroma!
Microwaves broadcast high frequency radio waves which cook from the inside out! Use your microwave to warm a good cup of coffee and last night's pizza, while your Food Dehydrator does the job for you.
Each herb has an ideal drying profile regarding technique, length of time and air temperature limitations. Some herbs like Rosemary, Greek oregano or Garden Sage will dry by simply hanging them upside down.
Other thick-leafed herbs like Genovese Basil may become musty when using the same technique. As you gain experience in managing the bounty from your herb garden you will find the best way to process the harvest based on your individual herb drying conditions.
Tender, freshly harvested herbs require careful drying. This can only come about in an environment of dry, circulating air of a mild temperature. The process needs to be accomplished quickly and at a low enough temperature as to not degrade the color, flavor or aroma of your hard earned herbs. Remember, the point behind drying is simply to remove enough moisture from the herb to allow for safe storage.
After ruining countless harvests in an oven and more so in a microwave, I found the only place to find this ideal herb drying environment is inside of a good Food Dehydrator; one that is designed for the job. A food dehydrator provides the variable temperature control and moving air needed for safe herb drying. Anyone who advises differently has not gone through the process of ruining a harvest while drying herbs!
Considering the cost of seed, time, effort and the potential heartache of a lost harvest a sensible and wise investment might be one of the various food dehydrators that are available. An excellent food dehydrator like the one below can be ordered online at a cost between $50 and $175 from suppliers like ChefsCorner.com.
In general, harvest the herbs just before blooms appear; early in the morning after the dew has dried. Cut annuals off at ground level, and perennials about one-third down the main stem, including the side branches.
Remove all of the old, lower, dead and discolored leaves. With the leaves on the stems, lightly wash herbs in cold running water to remove any soil, dust, worms, bugs, or other foreign material. Drain thoroughly and blot dry on absorbent towels.
Check drying directions on specific herbs available in the article section of our Herb Directory.
Hanging by the stem allows essential oils to flow from stems to leaves. Tie stems tightly in small ¾ inch bunches in a well-ventilated, dust-free area. To protect from bright light and to retain green leaf coloring, hang plants upside down in bunches in paper bags with the bottoms removed. The leaves are ready when they feel dry and crumbly, usually in a few days. If the herbs are not dry within a few days, you need more air movement.
Only after your refusal to invest in a food dehydrator -and don't say I didn't warn you!)
Take care to prevent loss of flavor, oils, and color. Begin with a small amount to prevent the toasting of a full crop, in the event of a "misjudgment." Following a gentle rinse and being blotted dry, spread the leaves over a paper towel on a cookie sheet or shallow pan not more than 1 inch deep.
Place the herb leaves in an open oven at a temperature of less than 110 degrees F (82.2 degrees C) for 15 minutes, then check and keep checking them. If the leaves begin to darken, the heat is to high! Reduce the heat and try again.
Experiment with each herb and the time needed to dry your herbs properly.
Good luck!