The height of summer is the time of collecting medicinal plants. And the collected raw materials must be dried to keep for the winter. And in this case, too, there are rules and important nuances — it depends on their compliance how effective the collected natural medicines will be.
What happens to the plant during drying
The healing effect of plants is due to the content of certain chemical compounds in them, and our goal is to preserve them as much as possible. But in a living plant, various biochemical processes constantly occur, as a result of which part of the active substances is destroyed (it is not by chance that the collection of medicinal raw materials is recommended to be carried out at a strictly defined time – when the concentration of useful elements is maximum).
Drying stops these processes: an aqueous medium is necessary for the activity of cellular enzymes. By removing moisture, we stop intracellular processes that lead to the transformation or decomposition of active substances. And accordingly, the faster we dry, the less we lose.
And, in addition, various microorganisms and fungi readily multiply in a humid environment – high-quality drying of medicinal raw materials protects it from such damage.
General rules for drying medicinal plants
Most medicinal herbs should be dried in the shade: under the influence of sunlight, the destruction of the useful compounds contained in them accelerates and the natural color of the raw materials changes. For some types of raw materials, drying in the sun is strictly prohibited; these include:
- any essential oil plants;
- glycosidic plants;
- the flowers and buds;
- large leaves, nettle grass.
Be sure to provide good ventilation: if you dry indoors— it should be ventilated; if you use an oven, do not forget to leave the door ajar; if you have the opportunity to dry raw materials in the oven, maintain traction, leaving the flap half open.
Where to dry medicinal herbs
If you regularly harvest medicinal raw materials, it is advisable to take care to equip a convenient place for drying it.
Ideally – ventilated attic under an iron roof. In summer, optimal conditions are created here: high temperature and good air circulation. If there is no attic, you can allocate a place for greenery on the street under a canopy or in a country house. In cold and humid summers, when there is not enough natural heat for drying, you can use a dryer or oven.
The grass can be dried by tying it into small bundles and hanging it on ropes or nails to the ceiling. But this method is not suitable for all plants — for example, the grass of the small gold digger turns yellow and moldy when dried in bundles.
You can dry the raw material by spreading it out in a thin layer on paper or fabric — this is the most versatile way. But it should be borne in mind that in the season of mass collection of medicinal herbs you will need a lot of space.
For drying flowers and inflorescences, fruits, seeds, it is good to use frames with stretched gauze or fine mesh mesh; a tray, a baking tray or a wide box with low sides will also be useful.
Temperature regime
The drying temperature depends on the type of medicinal raw materials. Thus, plants containing essential oils should be dried at a temperature no higher than + 35°C/95°F (at higher temperatures, the essential oil evaporates). Raw materials with a high content of vitamin C are dried quickly, at a high temperature (+70…+90 °C/158-194°F). Plants whose main active substances are glycosides also dry quickly (to stop the activity of enzymes that destroy these compounds), but at lower temperatures – +50…+60 °C (122-140°F).
Features of drying of some types of medicinal raw materials
It is best to do this in the sun; if the weather does not please, the raw materials are put on a baking sheet, covered with several layers of paper, which is changed as it is soaked with juice. The berries prepared in this way are dried in the oven or dryer at a moderate temperature.
The flowers and inflorescences dry quickly, providing good ventilation. It is undesirable to mix them during drying, so spread the raw materials in a thin layer. The large leaves are laid out one by one and turned over after the upper part has dried.
When using a dryer or oven, the raw materials are often over-dried. So that it does not crumble during packaging, turning into dust, it should be kept indoors for a while, allowing it to absorb a little moisture from the air, and only then spread out into bags or containers.
How to determine that the drying is finished
Well-dried raw materials, as a rule, retain their natural color (yellowed or blackened leaves, withered petals are evidence that the plant was dried incorrectly, and, most likely, its healing properties have been lost).
Berries and juicy fruits are considered dried if you squeeze them in your hand, do not get dirty, and the raw materials remain crumbly, do not stick together into a lump. The roots should break with a crunch after drying, and the leaves and flowers should be crushed into powder.
And where and how do you dry herbs for a home first aid kit?