The principle is simple; remove water contained in the plant as quickly as possible, while retaining the plants flavors and principal attributes. Generally, the flavor and quality of herbs is well preserved by drying.
Herbs keep their aromas intact :
Herbs that lose their aromas:
Conditions to dry herbs successfully
To reduce handling to a minimum during the drying process, keep the leaves on the stems. Group them in little bunches tied with a loose knot. For rapid drying, place the large leaves on a grate. Here, we have added a layer of screening to prevent them from falling between the large spaces of the grate.
As a rule, the higher the temperature the quicker the process. But be careful! Over approximately 35°C, essential oils evaporate and the colour and flavors deteriorate. Conversely, drying at to low a temperature delays the process and creates condensation, which alters the flavors.
Aeration plays an important role in this method. The humidity that is released from the plants must be rapidly eliminated.
Light discolours foliage and diminishes its quality. This is why picked herbs must always be placed in the shade.
Open air drying is the most common of all methods to dry a few small bunches. Depending on the quality of the conditions, fine herbs will dry in about four to eight days with this method. For larger quantities, a simple heating element, equipped with a ventilator, will accelerate the process.
- Suspend them upside down in a shady, well aerated space.
- If necessary, place them in a perforated paper bag to protect them from light and dust.
- Place a clean sheet below to capture seeds. The seeds fall as they ripen.
There are efficient dehydrators on the market. Some are simply made of superimposed plates over a grate. Others, more sophisticated and expensive, come equipped with a heat source.
An electric stove is not recommended, because its temperature control can be irregular. When the thermostat comes on, the temperature rises too rapidly and hence, it becomes impossible to maintain a constant temperature, near or below the 35°C limit needed for drying.
Microwave drying is rapid, but very delicate, as only a few too many seconds can mean the difference between dried and cooked herbs! Contrary to a convection oven, a microwave oven heats only the water contained in the plant tissues. The paper that wraps the vegetable matter absorbs the water and thus, the plant remains intact.
- About 1 minute: small thyme and rosemary leaves dry in a minute.
- About 3 minutes : mint and balm leaves, which hold a lot of water.
- Sage in particular must be watched because it contains essential oils that burn up at high temperatures.
Storage of dried harvests
- Place in airtight containers, well-marked and store in the dark.
- Do not grind them into a powder.
- In the first week, verify the state of the harvest daily and dry again if necessary.