- Rohan Hiatt
How is cannabinoid-rich hemp different from grain and fiber hemp?
Cultivation and Manufacturing Considerations
Industrial hemp has a plethora of historically-recognized uses. After the 2018 Farm Bill legalized hemp—characterized by THC levels below a 0.3 % dry weight threshold—at the federal level, the potential uses for industrial hemp in the modern market began to crystallize further. However, federal law has yet to recognize that for many hemp end-products, the THC levels of the harvested plant matter are irrelevant.
Hemp farming is traditionally separated into three categories based on the desired end-product and the portion of the Cannabis sativa plant used to make that product. Hemp is harvested for either its fiber, seed, or flower. Each of these categories requires different cultivation and manufacturing processes, resulting in very different end products.
Hemp fiber in particular has a long history of commercial use in textile manufacturing and tends to be more durable than other fibers used to manufacture fabric and other textile products. Hemp stalk and hurd also have a myriad of uses, including for building materials and biocomposites. Hemp seed, a type of oilseed, has gained similar historical recognition for its nutritional qualities. Hemp grain contains all nine essential amino acids and represents a robust source of antioxidants, essential minerals, and healthy fats. Lastly, hemp flower is grown to produce cannabinoids, such as cannabidiol (CBD) and cannabigerol (CBG), for various pharmacological purposes. Cannabinoids are chemical compounds naturally found in Cannabis plants that interact with the endocannabinoid system, which regulates certain physiological and cognitive processes in humans. Importantly, cannabinoids are concentrated in the plant’s flowers, and do not manifest as prominently in the stalk/fiber or grain.
Cannabis plant genetics play an important role in delineating between the three main categories of hemp. Specific varieties of Cannabis, called cultivars, are grown because they exhibit traits that are desirable for certain end products. These traits are not always directly related to THC levels in the plant, making current regulatory testing requirements less necessary for fiber and grain operations compared to cannabinoid-focused operations.
Fiber cultivars express different genetic characteristics in the fully-grown plant more appropriate for the types of manufacturing processes associated with hemp fiber. Some varieties focus on producing quality “bast” fiber, the long and durable inner bark of the hemp plant. Other varieties focus on producing quality “hurd” fiber, the inner woody core of the plant. For fiber cultivars, the relative cannabinoid levels are only relevant insofar as they affect the physical characteristics of the bast and hurd fibers themselves. Similarly, farmers choosing cultivars for hemp seed production are less concerned about cannabinoid levels and more interested in the nutritional value of the hemp grain and hemp seed oil. These considerations are bolstered by the fact that fiber and grain cultivars are well-researched, and many strains exist that result in desired specifications for end-product manufacturing.
On the other hand, cannabinoid-rich hemp cultivars focus on the relative levels of specific cannabinoids like CBD and CBG. Additionally, cannabinoid-rich hemp farmers almost exclusively utilize feminized seeds or clones to ensure that they only grow female-sexed plants. This is because male-sexed plants can reduce overall yield and value by pollinating female flowers. Thus, unlike fiber and grain, hemp grown for cannabinoid extraction requires genetic selection practices that focus on the cannabinoid content itself, and therefore need testing to ensure a viable crop—biologically and legally.
Compared to hemp grown for cannabinoid production, growing hemp for its fiber and seed tends more toward large-scale, industrial operations. Harvesting fiber and grain typically requires the use of traditional agricultural equipment and machinery (often retooled for the unique needs of hemp farming), whereas cannabinoid-rich hemp is grown in smaller batches, with horticultural practices, and involves more “hands-on” labor.
Post-harvest practices differ significantly, as well. For example, hemp seeds may need to be dehulled and cleaned if intended for human consumption and fibers go through a process called “retting” to facilitate fiber separation while eliminating excess organic matter. Cannabinoid-rich hemp requires more methodical post-harvest processing to preserve the cannabinoids and other compounds concentrated in the flower. However, larger flower grow operations sometimes sacrifice preservation of the full spectrum of cannabinoids in favor of higher volume harvesting of biomass with a focus on maintaining consistent CBD levels.
As a result of the large-scale nature of hemp fiber and grain operations, mandatory THC-based testing requirements are particularly burdensome and provide minimal informational value. They also do not serve any risk alleviation purpose due to the nature of the most prevalent fiber and grain end-products.
Hemp fiber products generally help alleviate the over-extraction of timber from forests and provide a natural alternative to harmful synthetics. Significantly, this means that hemp fiber represents one of the best solutions to help combat climate change by reducing reliance on environmentally destructive processes. Fiber is used in novel building materials like hempcrete and hemp “wood.” Bast fiber specifically is used to produce insulation and fabric, while hemp hurd’s absorption properties make it ideal for fiberboard, animal bedding, and compost. Hurd can also be used as a component in plastic and paint manufacturing.
Hemp seed grain produces a diverse variety of products, as well. Whole seeds are used in animal feed (note, federal approval for hemp as animal feed is still needed) and hulled hemp seeds are used in products for human consumption, such as hemp hearts. Hemp seed oil is similarly used in food products, along with cosmetics like lip balm, lotion, and soap. Despite the fact that grain products are consumed by humans and animals (pending approval), the predictability of genetics and the manufacturing process for grain limits the risk of intoxicating cannabinoids reaching significant levels.
Furthermore, the majority of cannabinoid-rich hemp products use extracts derived from the flower or the whole plant, in dried or otherwise processed forms. Because these products are consumed for cannabinoids, they tend to come in forms that help activate the pharmacological effects. Cannabinoid-rich hemp products include CBD lotion, CBD food products like chocolate, and CBD tinctures.
Compared with grain and fiber hemp, cannabinoid-rich hemp exists as an entirely separate commodity class, with very different manufacturing considerations and end-product goals. Therefore, while THC-based testing requirements may remain appropriate for cannabinoid-rich hemp products, they make little sense in relation to fiber and grain products due to the low risk of THC levels throughout the production and manufacturing processes.
Jolene Hansen, A Deep Dive into the U.S. Hemp Grain Industry, Cannabis Bus. Times (Dec. 16, 2021), https://www.cannabisbusinesstimes.com/article/deep-dive-us-hemp-grain-industry-outlook-cultivation-processing/
Hemp Cultivation: Growing for CBD vs Seed and Fiber, Tonic (Apr. 27, 2020), https://www.tonicvibes.com/blog/hemp-cultivation-growing-hemp-for-cbd-vs-hemp-for-seed-and-fiber/
Navdeep Kaur et al., Uses of Raw Products Obtained from Hemp: Fiber, Seed, and Cannabinoids, Agronomy Dep’t Univ. of Fl. (Sept. 16, 2021), https://edis.ifas.ufl.edu/publication/AG459