Fresh herbs are welcome in just about any kitchen, however, drying herbs to perfection is critical for use in the kitchen or for extracts purposes, i.e. health & beauty or medicine.
A lot of the dried herbs we buy at the grocers are often irradiated for preservation and well past their peak potency. Typically, these herbs have been mass produced in the field using conventional agricultural practices and harvesting methods.
Comparatively, after drying herbs carefully that have been homegrown, you may find the differences in your dishes or extracts simply “night and day” over commercial store bought.
Here’s what you need to know to harvest and dry your herbs for maximum potency, like a pro.
Trichomes (notice the dried resin capped trichomes in photo BELOW) are delicate, especially when dry. Rough handling when drying herbs can break off these tiny and potent parts of the plant that often hold the qualities of the crop harvest. Also note that in some types of herbs, most of the resin covered trichomes are found in highest concentrations around flower bracts).
Essential oils and the aromatic compounds they contain are also delicate—but in a different way. They have a life cycle too; similar to a plants lifecycle where there is such a thing as peak maturity. Lots of air movement or excessive heat will damage the quality of the aromatic compounds in the harvest—therefore, drying herbs is not a process to be rushed.
Aging Resins & Essential Oils
Usually for culinary purposes, the quality of your dried herbs (ie basil) will start to decline over time, highlighting the value of good storage (more on storing your harvest HERE)
However, in some instances some of the qualities may improve over time with careful storage and controlled exposure(s) to air. For example freshly extracted essential oils will often improve in terms of aromatic qualities after aging at room temperature in the dark for about a month or so. For example in spearmint oil extracted via steam distillation, when freshly produced there is a slight “burn” smell to the oil. After a month of careful storage this disappears leaving a very potent aromatic quality to the pure spearmint oil simply from being left to “breathe” for a short period.
Important: Strong light will hurt the quality of the resins and oils in your herbs and flowers after harvest—AVOID EXPOSING YOUR HARVEST TO STRONG SUNLIGHT during drying, curing and aging processes.
This is a different type of aging—one that is more immediate than we discussed above. As stressed previous, drying shouldn’t be a rushed process. In most basic terms, the initial process requires two important steps, and those are:
i) Drying, to remove the bulk of the moisture content to prevent spoilage when stored. This process usually lasts 4-7 days in most cases
ii) Curing, removing the “green” qualities in the aroma and flavour; i.e. dissipating “fresh” notes. To some extent, the resins and essential oils will take longer to cure than the plant material itself. This process usually lasts 10-30 days. A an Aging process as described above may also follow.
Is it Better to Hang Dry the Whole Plant versus Screen Drying?
This can be an area of debate amongst seasoned gardeners. There are some advantages to drying the whole plant, for example on lines like HERE
TIP: Try harvesting whole branches, trimming away what you don’t want while fresh—hang the manicured branches from a line. This way, you get a lot of the advantages while cutting down on the disadvantages associated with drying whole plants.
Erik Biksa has been writing about and discussing hydroponics growing, related technologies and cropping methods since 1999 in a variety of professional publications and platforms globally Erik has travelled the world learning and teaching modern growing techniques and technologies and is appreciated by many growers for his informative yet hands on approaches. Presently, he is the Editor at Grozine Hydroponics Mag.