Like any product that is ingested, cannabis has a shelf life.
Manufacturers of infused cannabis products such as candies, beverages and creams need to make sure their products can withstand time on store shelves and in customers’ homes.
“Shelf-life stability in the world of cannabis-infused edibles is essentially no different than it is in the world of regular food products or dietary supplements,” said Drew Hathaway, senior scientist at Commerce City, Colorado-based Stillwater Brands. “The three key pillars of shelf-life stability for any industry should be understanding how your product’s physical, chemical and microbial stability can potentially change over the full duration of the product’s shelf life.”
What Is Shelf-Life Stability?
Shelf stability refers to both the length of time a product is at its sensory best and, for foods that spoil over time, a direct measure of product safety, said Scott Riefler, chief scientific officer for Sōrse Technology, a Seattle-based CBD emulsion ingredient supplier.
“Of course, food safety is the paramount concern,” Riefler said. “This is followed by consumers liking the product, which drives brand loyalty and repeat business.”
There are three distinct shelf-life terms:
- Best-by date.
- Expiration date.
- Sell-by date.
The best-by date is not the expiration of shelf life. It’s the time frame during which all the ingredients and product attributes are at their best, including sensory characteristics, color fastness and flavor intensity. Ingestible products—including cannabis edibles—can be consumed safely well past their best-by date.
The expiration date indicates when a food is no longer safe to consume from a spoilage standpoint or a point in time when the preservative system is no longer active and harmful microbial activity might be present.
The sell-by date is used for foods that require special storage such as milk or meats. It represents the last date the product should be purchased, but how long it remains safe to consume is based on the consumer’s storage method.
The shelf life stated on the label is often significantly shorter than reality stated on a product labeled “sell by” or “best by.” However, there could be microbial issues if a product is past its expiration date.
Cannabis edibles have a shelf life similar to their non-cannabis counterparts, Riefler said. THC and other cannabinoids don’t go bad—but they do slowly lose their potency over time, so most infused products are labeled with a best-by date rather than an expiration date.
“If you have eaten a cannabis edible past its best-by date, you shouldn’t be concerned,” Riefler said. “If you have consumed something that is past its expiration date, you need to be aware of the potential microbial issues.”
According to Hathaway, the three pillars of shelf-life stability for cannabis-infused products are:
- Microbial stability: Is my product safe to eat for its full shelf life?
- Chemical stability: Does the THC/CBD content of my product stay the same throughout its shelf life and stay within the allowed variance range defined by my state’s legal program?
- Physical stability: Do the flavor, texture or other sensory attributes change over time?
“Chemical stability is an aspect of shelf life that gets extra attention in the cannabis space, as that is the main factor that will determine how much THC, CBD or other cannabinoids are present at the time of consumption,” Hathaway said.
“Physical stability is often intertwined with a product’s chemical and micro-stability, which is why all three are important to monitor over time,” Hathaway said. “All three aspects can be controlled and even predicted by a sufficient understanding of the product formulation, production process and packaging.”
Knowledge around how to create and evaluate shelf-life stability of food and beverage products is well-established through decades of research and experience, Hathaway said. But because the cannabis industry is so young, scientists are still learning some of the fundamental attributes about incorporating CBD and THC into food and beverage products, he said.
“Formalized, properly designed research studies can finally be conducted by reputable researchers, which will continue to add to this knowledge base,” Hathaway said. “The industry continues to rapidly evolve its learnings, which will only continue to accelerate as legalization spreads to new states and countries.”
Testing for shelf stability before launching any product is essential to ensure you’re providing a consistent and safe experience for your customers, regardless of whether the product they purchased was produced yesterday or is at the end of its shelf life, Hathaway said.
Graham Farrar, CEO of Carpinteria, California-based Glass House Farms, said test results are good for 12 months. He said producers of cannabis products should be asking:
- What is the legal lifespan of a product?
- What is the quality lifespan of a product?
“Flower is probably the most sensitive,” Farrar said, adding that flower dries out and loses its potency over time.
Some extracts are quite durable, Farrar said. Gummies made with distillates have a long shelf life as long as they’re not left in a hot car. Extracts such as live resins and rosins don’t get better with age. However, resins stored in a cool, dark spot should have a fairly lengthy shelf life.
The Role of Packaging
Packaging plays a key function in the shelf life and safety of cannabis products. It provides a barrier to the surrounding environment, keeping contents sanitary and microbe free. It also prevents oxidization and, in the case of beverages, stops ultraviolet light from attacking liquids.
“Since packaging is the only physical barrier between the product and the outside environment, its importance should not be underestimated,” Hathaway said. “Ideal packaging will prevent the food product from being exposed to external oxygen, moisture and light, as all three aspects can negatively affect a product’s chemical, microbial and physical stability.”
Simple barrier films are sufficient packaging for products such as confections that are not susceptible to spoilage because of their low water content. For products where there is potential for spoilage or microbial growth, oxygen barriers are needed.
Packaging for cannabis flower should protect the contents from light and have a true vacuum seal. Beverages and concentrates should be refrigerated to keep them in prime condition.
Appropriate packaging also is crucial for THC- and CBD-infused topical items such as lotions and salves, said Kat Merryfield, founder of Dunlap, Tennessee-based Kat’s Naturals, which produces a line of CBD products.
Merryfield’s packaging is modeled after the cosmetics industry. The double-walled jars used for Kat’s Naturals CBD creams withstand heat, and its tinctures are in dark bottles.
“If people are using water-based lotions, they should be in pumps or squirt bottles,” Merryfield said. “Water holds all kinds of bacteria. Once that gets in the oil, it begins to grow.”
Labels on packaging should have basic instructions for how to properly store the products.