The proper storage of harvested hemp is as crucial as every other step in the cultivation process. It is the one final factor that determines whether or not you’ll earn as much profit as possible on your harvest.
In the United States, the cannabis industry’s understanding of best practices for hemp biomass storage is an ongoing learning process. Most of the methods currently being practiced are based on earlier generations’ grasp of the fundamentals, and information gleaned from the industry in other countries.
Whereas, elsewhere, with knowledge gathered over years of hemp growing and processing, many countries have developed increasingly innovative storage methods for hemp products; and with more nations seeking the legalization of crop as a legal commodity, you can imagine how fast this innovation is happening.
THE SCHOOLS OF THOUGHT
Industry experts say there are two schools of thought on the harvesting and processing of hemp for its phytocannabinoid extracts.
- Those who seek to maintain top-quality buds with a high-terpene profile (attainable, but laborious. Growers have to tend to the hemp plants in a marijuana fashion, hand-harvesting only the flowers).
- Those who seek quick harvest, and thus carry out whole-plant extraction. This method is similar to how hemp fiber, straw, and other conventional crops are harvested.
However, growers can also resort to combining both methods in their operations. Here, the hemp flowers are cut off the top of the field-grown plants, and then the remaining biomass is collected with a combine harvester.
Finding a suitable market is another issue. Many businesses have had to hold on to their products for longer than they expected.
Unfortunately, even with specialized storage facilities, there are still battles to be fought: At certain levels, factors like light, temperature, and humidity will turn an excellent batch of hemp into a deplorable mess.
THE STORAGE QUANDARY
It wasn’t so long ago when hemp became the new gold. Farmers raced to join in on the craze, with visions of hundred-thousand-dollar profits for every acre of crop dancing in their heads. While all this happened, observers began to wonder if the hemp market could absorb the sudden uptick in production.
Then, as they predicted, prices began to fall. With no mechanism to cushion the shock, overproduction had invariably led to oversaturation. Profits went south, and farmers became desperate for solutions.
Hemp is inarguably a high-risk crop, and unlike most other major crops (corn and other grains, for example), it requires more complex specialized storage equipment and protocols; and finding one has proven difficult.
From dealing with unexpected costs to trying out several facilities, and failing in search of the right one, growers have had to deal with a whole lot.
But, that is not all. Sometimes knowing what to do isn’t enough; growers need to know HOW to do it.
For the most part, the biggest concerns that growers have to worry about are humidity, UV light, and temperature when setting up a controlled storage environment.
Humidity has been an all-time enemy of agricultural produce, and it is no different with hemp: all varieties of hemp are susceptible to mold if not dried properly, or if stored in conditions of high humidity.
So, before taking the harvest into a climate-controlled space for storage, growers must first ensure that moisture content in the biomass has been reduced to a tolerable minimum. Once that is done, an optimal relative humidity range of 55 – 65% should be maintained for effective long-term storage.
According to Chavis of Paragon Processing, drier biomass is always the best choice for maintaining the integrity of the phytocannabinoids. He said, extracting biomass with higher moisture content will raise the phytocannabinoid percentage loss up to 20%.
Note: Extremely low humidity could render the flower dry and brittle, ripping it of its essential oils and aromatic compounds.
Ultraviolet Light (UV Light)
“If you have UV exposure, the CBD will degrade,” – Robert Leaker, Eureka 93
Light is radiation, and with sufficient energy, can degrade organic materials. This is one of the reasons flash photography is not allowed in museums.
The Science: When sufficiently energized, this radiation, which emanates from the sun as well, knocks off electrons in atoms to form ions. Unfortunately, this “ionizing radiation” is detrimental to living cells and their DNA; hence, the term “sunburn.”
Multiple studies have shown UV-light to be a primary contributor to cannabinoids breakdown. For this reason, hemp bales are preferably wrapped in white plastic, an efficient way to keep sunlight out.
“You want to keep it dark, keep it dry and keep the oxygen out of it,” Leaker said.
Growers face a classic Goldilocks scenario with temperature control.
Mold and mildew are bound to thrive on organic matter when the temperature is too low. But keeping the temperature high will inadvertently lead to the drying out of cannabinoids and terpenes.
Thus, taking cue from Paragon, ideal hemp storage temperatures are between 68 and 78 degrees Fahrenheit.
How long is too long?
“Generally, when you take an agricultural product and dry it down to a certain percentage of moisture, it will stay as long as you’re keeping it in a climate-controlled environment,” said Propheter.
Usually, freshly dried hemp is the preferred choice for cannabinoid extraction. But, if stored properly, preserved hemp will also yield great results – so long as it is not kept for too long.
According to Propheter, hemp flowers and biomass can be preserved for up to a year. However, even when stored correctly at the right temperature and humidity level, cannabinoid degradation is still a possibility.
So, evaluating stored hemp crops regularly and before extraction is necessary. In doing this, some specific traits to look for include color, smell, and texture: it should be nice, clean, green, and dry with a good smell.
SCALABLE AND EFFECTIVE STORAGE SOLUTIONS
Again, there is a bulk of raw material on the market, and prices are falling.
Most hemp farmers grow hemp for CBD because they believe that is where the most profit is to be made. And, they are not wrong, CBD currently sees the most activity in the industry.
Thus, the market needs to expand for other hemp derivatives. Until that happens, farmers might have to keep dealing with oversupply and will need to learn how to store their harvested crops properly.
Now, some of the most efficient storage solutions for harvesters and hemp growers include:
- Hopper Bins: One of the best storage solutions for hemp. With adequate aeration, hopper bins preserve hemp harvest from light, humidity, and heat. However, it is more suited for industrial and large-scale productions.
- Mini-Bulk Bags or Tobacco Bags: According to Propheter of Criticality, hemp can be preserved in a tobacco storage system. When fitted with forced-air units, tobacco barns can be used to dry and store hemp produce.
Choosing the best storage solutions is not a one-size-fits-all. Different strokes would suffice for different growers. Growers have to consider additional critical factors such as the size of farm, quality of set up, and the scalability of the medium.
Therefore, it’s advisable to take it one step, evaluate all factors, and logically test all conditions to boost the chances of determining the best-suited storage conditions, and ultimately attain the best quality products.