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©2008 Alaska Herb Tea Co.
Anchorage, Alaska
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DRYING & PROCESSING

Drying will be critical to your success as an herb harvester. You may be able to locate a world-class field of valuable wild herbs & gather them in record time; you may be able to transport them quickly to your drying area in perfect condition; you may pick & sort out every stray blade of grass & all foreign matter - but if you don' t dry them properly they will be worthless.

Different plant parts are dried differently, but two key factors affect all drying operations: heat & airflow. The fresh plant material must be heated enough so that the water inside will evapo­rate out, but not so much that the fragrance & volatile oils are lost or destroyed. Likewise, air must flow around the plants so that the evaporated moisture is carried away, but not so much that the outside of the plant dries before the inside, thus locking moisture in. When you are using any kind of "drying box" in which you control the heat & airflow, the rule of thumb is: begin with low heat, rising it gradually during the drying process; begin with slow, but adequate airflow, increasing it gradually. In general, drying temperatures should not exceed 120°.

YOUR BASIC DRYER

Diagram one shows the construction of a simple, basic dryer, which could be constructed for less than $100 & would be sufficient for drying the harvest of a moderately ambitious forager throughout the season.

This drying box is constructed from plywood or masonite & firring strips. The dimensions are meant to use the 4 x 8 sheets most efficiently. The drying racks inside are standard aluminum window screens. The heat source is a small propane catalytic element. Air enters the box through holes in the back near the bottom, is heated, rises through the screens & plant material & vents through holes in the top. Holes should be at least 5/8" in diameter. Covering some of the holes on top when drying begins & uncovering them as it progresses can control airflow. You can also mount a small bathroom type vent fan on top to control airflow. A thermometer should be mounted on the inside of the door about halfway up. The catalytic heater will have a regulator for heat control. After a little practice you will be able to adjust the heat & air flow accurately. You will find this dryer very serviceable & durable. It operates well outdoors in any weather, as long as it is under a tarp.

If you need greater drying capacity because you harvest lots of material, or because you buy fresh harvested material from other foragers, you can consider doubling this one by having two sets of screens side by side, & two drier doors, like a two-car garage; or you can consider having several dryers, so you could custom dry separate crops separately (this could also save you from having to heat up a large dryer on days when you don't have a full load). If you still need more room, or if you are cultivating & therefore will have large harvests of one crop all at one time, you will need an industrial walk-in dryer.

 DRYING PROCEDURE

Open-air drying is possible & very economical, but the unpredictable weather will determine its success or failure. The principal is simple. Your crop is spread out on a suspended sheet of porous material - a bed sheet, canvas, mosquito netting, screening; it is kept out of direct sunlight - under a tarp or tree; it is turned often; the weather stays clear & dry for three days & nights. With ideal weather conditions, you will be able to dry almost any crop outdoors. Actually, all crops, except for color & oil crops, should be pre-dried outdoors. Pre-drying is accomplished by spreading your fresh crops out onto a suspended screen or sheet as soon as possible after harvesting. You should go through & loosen up any plant material that may have become compacted in your harvest sacks, & you should pick through to remove unwanted plant spe­cies, old, discolored or insect-eaten leaves & foreign materials. By letting your crop sit outdoors for 24 - 36 hours, some of its moisture will evaporate & the material will decrease in volume, so you will be able to fit more into your drying box & you will have to operate your dryer for less time. Outdoors pre-drying also gives all the little critters that you unknowingly harvested along with the plants a chance to hop off & escape - if you bake these little critters in your dryer you will have to pick them out by hand.

After pre-drying, move your crop onto your dryer screens & into your preheated drying box. Spread the plants uniformly over the screens no more than three inches deep. The crop should be turned every four hours for the first day & then as necessary until dry. Turning keeps the plants in the middle of the pile from molding. Your crop is dry when it crackles. Maximum recommended moisture content is 8%, less than 5% is best. Be sure that it is uniformly dry, because any pockets of moisture in your stored product may degrade the whole lot.

Generally, roots & bark may be dried at higher temperatures than other plant parts.  Drying temperatures for them may start above 110° & may reach 170°. Leaf matter & herb material should be spread evenly & dried at temperatures beginning around 90 - 100° increasing to 120°. Flowers, or color crops, should be dried at more consistent temperatures, about 90 - 105° & should be spread thinly. Any moisture left in these crops will destroy the color rapidly in storage. Delicate crops with high oil content need to be dried with extra care. They should not be dried or pre-dried outdoors. Beginning temperatures should be lower (85°), they should be watched carefully & turned often to preserve oil content & quality.

Packaging and Storage

Technically, all products are in storage during the interval between harvest and consumption. Proper storage is what assures that your high quality produce will still be high quality when it reaches the end user. After your product is dried, your main concern is that it not be exposed to moisture, sun, high heat, wind, fumes or dirt.

Polypropylene sacks are good storage bags for most crops. Polyethylene-lined boxes are also good, especially for crops you do not want to have crushed. Likewise, fiber drums are good. Burlap bags can be used for storing and transporting bark and root crops. For short-term storage and trans­port, large plastic bags will suffice, although it is best to protect them in boxes or burlap bags to avoid tearing.

Each package, sack or box of plant matter should be labeled or tagged. Each tag should bear the producer's or the seller's name, address, contents, net weight, area and date gathered.