View Full Version : Harvesting and Preserving of Herbs

Wednesday, November 2nd, 2005, 01:06 PM
When to Harvest

Most herbs can be snipped for the small amounts needed for cooking almost as soon as they grow larger than a few inches. However a major cutting to harvest the herb is best done when the plant is mature enough to withstand the stress (in the case of perennials) or fully- developed and at its peak (in the case of annuals). There are two considerations in deciding when to harvest; time of day and time of year.

Determining the optimal time of day to harvest herbs is fairly simple. The best time is mid-morning, after any dew has evaporated from the leaves. This is also the optimal time to harvest herbs in order to maximize the essential oil content that provide the flavor we crave.

Since most herbs are preserved through drying, the trick is to minimize the amount of water on the plant material you are harvesting. Ideally, the plant leaves should be dry to the touch. Wait at least a full day after rain (or use of sprinklers) to insure a dry plant surface. If necessary, spray them with a hose the day before harvesting to remove dirt or stray insects. The time of year that a herb should be harvested can vary tremendously. It depends heavily on the herb's growth pattern (e.g. annual versus perennial) combined with the growing region in which you live. For example, in Southern California where the climate is classified as "Mediterranean", many herbs can be harvested several times throughout the year, even as late as Thanksgiving. However, the same herb growing in a Canadian garden may have just barely enough time to reach maturity before the Arctic winds shut down all growth.

Here are a few hints to help you decide when to harvest.

Root Crops - Herbs such as garlic, ginger, and galangal are best harvested in the fall when the leaves start to yellow and the plant is preparing for a dormant period.

Annual and Biennial Herbs - Basil, summer savory, parsley, and other annual or biennial herbs grown for their leaves can usually be harvested periodically during the growing season. In fact, basil benefits from regular harvesting, which will prevent it from going to seed and completing its life cycle. Those of you in colder climates should also remember that your shorter growing season and harsher winters make it necessary to treat some true perennials as if they were annuals.

Flowering Herbs - Edible flowers from herbs such as roses, lavender, borage, and pot marigold are best harvested when the flower has just opened. The flower petals, ovary, and calyx are all firm and at their maximum freshness at this point.

Seed Herbs - Herbs that produce seeds require the most precise timing for harvest. You must wait until the seeds are fully ripe, since no further ripening or improvement in flavor will take place after the seedhead is separated from the plant. Once maturity is reached, harvest immediately to maximize the amount of the seeds you capture. Delaying even a few days can result in loss of the seed crop to hungry birds or scattering of the seeds due to high winds or other weather conditions.

Perennial Leaf Herbs - Perennial herbs are the easiest to harvest. In general, you can harvest any time during the growing season when enough plant material is available. My only caution is to avoid harvesting in late fall. Late harvesting can stimulate growth of tender shoots that will not have time to harden before winter hits. It can also deprive the plant of its natural buffer zone against drying winter winds that cause "die back" and sometimes the death of the plant.

Harvesting Techniques

The technique used to harvest the herb depends on what part of the plant is required. Here are some examples from the more common herbs. In all cases, if you are harvesting more than a handful, have a dry, clean container (basket, bucket, paper bag) for the cut branches. Once they are cut you need to treat them as you would food, keeping them away from dirt and contaminates.

Chives - Cut chive leaves to within about an inch of the ground. Since the heart of the plant is in the underground bulb, they can withstand this extreme cut.

Basil, Mint, and Other Square-Stemmed Herbs - Cut branches down to a node where there are leaves or side shoots. This will encourage existing shoots or dormant growth buds to branch out, resulting in a bushier plant. Leave at least six inches (15 cm) of the plant so that it will still have enough leaves to produce food.

Dill, Caraway, and Other Seed Herbs - Have a large paper bag ready to receive the ripe seedheads. Cut the stem below the seedhead and place it immediately in the bag. Since ripe seeds easily fall from the seedhead, be sure to minimize handling prior to securing the seedhead in a container.

Sage, Thyme, and Other Woody-Stemmed Herbs - Perennials that develop woody stems after the second year are best cut down to portions of the woody stems. You may find that harvesting is a good time to shape the plant to your liking by severely cutting back rogue branches.

Lavender and Other Flower-Producing Herbs - When the flower head is what you are harvesting, cut the flower stem as far down as is appropriate for the plant. For lavender, cut down to where the leaves begin. For roses, cut the stem back to where there is a five-leaf branch or where the stem is at least the thickness of a pencil, whichever comes last.

Drying Methods

Now we come to the most difficult part of preserving our herbal harvest. In drying herbs, we have two dangers to avoid. First we must not dry them so fast through high temperatures that the essential oils are driven out along with the moisture. Second we do not want to dry them so slowly or with inadequate air circulation so that molds and fungus destroy our crop. With those caveats, here are some drying methods that have proved successful for myself and other herb harvesters.

Hanging Bunches - First, you must tightly tie your bunches or twigs together. While drying, the stems will shrink and can drop from the bunch if it is too loose. Second, close bunching of some high-moisture herbs, such as basil, can result in uneven drying and even mold in the inner core of the bunch. Third, you have to be careful to find a relative dust-free area (this is food, after all), with good circulations, and warm temperatures for this to work well. This almost requires the dedication of a room to the process. Nevertheless, this method does generally work.

Screen Drying - This method is a step from the hanging bunch, although it requires more "real estate" in your home. Take an old window or door screen and place it horizontally on a support with several inches of clearance underneath to allow for air circulation. Place the herbs on the screen in a single layer. If you must double up your herbs due to space considerations be prepared to stir or rotate them at least once a day to avoid rotting. As with the hanging method, try to place this in a relative dust-free area , with good circulations, and warm temperatures.

Using the Oven - This is the "speed dry" method that was very popular before the advent of microwaves. One method is to turn on the oven to its lowest setting for five minutes to heat the oven. After turning off the oven, place the herbs on the oven racks and close the door, leaving the herbs there for several hours or until the oven chamber returns to room temperature. Repeat the process, as needed. Avoid keeping the oven on while the herbs are in the oven as this is likely to drive out too much of the essential oils from the leaves.

Microwave Oven - Using the microwave is fast, but risky. You must remember that all microwave ovens do not uniformly heat the contents of the oven chamber. There are always "hot spots" and "cool spots". In the microwave I have sometimes had part of my herbs slightly burnt while other parts were not yet dry. You can only effectively dry small amounts at a time. To microwave, first remove the stems of the herb from the leaves, if this can be conveniently done. Then place a handful of herbs on a paper towel in the microwave. Microwave on high for one to two minutes at a time, depending on the wattage of your oven and the thickness of the herbs. In between microwaving, stir the herbs around on the towel and allow any excess moisture to escape from the oven. With a little experimentation, this process will work fine for small quantities.

Paper Bag - This is one of my favorite methods to dry moderate amounts of herbs. Take a clean paper grocery bag and place the herbs in it, tips down. Do not pack the bag with herbs because you want to allow for air circulation. Place in a warm, dry spot. Stir the herbs daily until the leaves are dry and will break off easily from the stem. This method is especially good for herbs with small leaves (e.g. thyme, rosemary) or seeds because they won't fall to the ground as they would with a screen or by hanging.

Home Dehydrator - If you are fortunate enough to have a home dehydrator then, by all means, use it for your herbs. It is specifically designed to remove moisture from fruits and vegetables so it will have no trouble with herbs. Be sure to follow the manufacturer's directions for optimal results.

Do you have room in your freezer? Chives, rosemary, basil, fennel, dill and parsley are examples of herbs that freeze well for fresh use later. You need to blanch the herbs first by placing them in boiling water for one minute, and then immediately immersing them in very cold water. Pat dry thoroughly and transfer to plastic baggies and place in the freezer.

Again, labeling is a culinary virtue for the inexperienced. If you think identifying dried herbs can be tough, you're really in for a challenge when you wish to defrost the proper herb for a special recipe!

Source (http://www.pagansunite.com/modules.php?name=News&file=article&sid=139)