Cannabis is a relatively new part of the well-established agriculture industry and brings with it novel challenges to assure that its use in foods and drinks for medicinal and recreational purposes will be safe for consumers. Businesses are showing a lot of interest in using various parts of the cannabis plant in edibles and beverages, including Ben & Jerry’s, which said in 2019 that it planned to offer a cannabis-infused ice cream. U.S. sales of drinks infused with cannabidiol (CBD), a non-intoxicating chemical obtained from hemp, are expected to grow to more than $1.4 billion in 2023, up from $86 million in 2019, according to researcher Zenith Global’s Beverage Digest. That’s on top of sales of medical and other cannabis edibles.
Hemp and marijuana are in the same cannabis plant family, Cannabis sativa. The difference between them lies in the amount of the psychoactive ingredient tetrahydrocannabinol (THC) that they can contain. A key issue in widespread adoption of cannabis-infused products is that, on a federal level, cannabis and CBD-infused foods still aren’t legal. That’s partly due to health and safety concerns such as potential liver injury, drug interactions, male reproductive toxicity, and side effects such as drowsiness.
States where cannabis is legal each have their own requirements for product testing and remediation. That means a mold or yeast level in a cannabis flower may be acceptable in one state but not another. Mold and yeast are two of the main culprits causing cannabis products to fail a state safety test, but laboratories also test for other microbes, mycotoxins, pesticides, heavy metals, water content, residual solvents, and terpenes, which are the flavor and scent components of cannabis.
“A lot of regulations have been made in a very short period of time that aren’t really based on too much scientific fact,” says Ketch DeGabrielle, a cannabis consultant with Qloris Consulting in Boise, Idaho. Formerly, DeGabrielle was operations manager at Los Suenos Farms, a large-scale cannabis farm in Avondale, Colo. He specializes in designing harvest and processing systems.
DeGabrielle says that most states look at total numbers of yeast and mold in cannabis. However, some yeasts live compatibly with the cannabis plant and keep dangerous molds from taking hold, he adds. “So, looking at everything in totality, we’re not really getting a whole picture that way,” he says. “We’re just saying it can’t have ‘x’ amount of a certain fungus.” But not all fungi or bacteria are harmful or will cause a health problem if infused into food or drinks.
Any moist cannabis plant can develop yeast or mold, just like other agricultural products, he says. When the cannabis plant is harvested, the bud or flower is wet, and it’s important to lower the moisture content within seven days after harvesting. Cannabis and hemp are dried in different ways because the sun degrades the THC potency and heat can diminish the taste and scent of the plant’s terpenes.
Some states also test for Aspergillus, Salmonella, and E.coli, which DeGabrielle says is good practice because those microbes are all dangerous to people. But he and others say more specific testing of microbials needs to be done.
The Cannabis Microbiome and Testing
Brianna Cassidy, PhD, an analytical chemist at CDX Analytics, a cannabis testing laboratory in Salem, Mass., says there’s a lack of knowledge of what is actually present in the microbiome of cannabis, because it is comparatively recent to the agriculture industry. “It can host a plethora of different microorganisms, but there’s only been a few decades for this plant to be heavily studied,” she said. “So, we have to figure out what living things are present that need to be tested for.”