How temperature and humidity impact the storage of cannabis over time and what you can do about it.
With all the reasons to spread cheer, you might not want to store your cannabis for too long over the holidays. However, some people are leaving for the holidays and may need to leave their medicine behind. If you need to store your cannabis for a while, proper storage will ensure you return home to a present of your own wrapping.
When storing your cannabis, don’t forget to control for temperature and humidity.
In 1976, Fairbairn et al. published a paper that documented the stability of cannabis under varying storage conditions. [1] They showed that light exposure was the number one predictor of cannabinoid decomposition. Air oxidation also led to degradation. The easy fix is to turn off your lights and place your cannabis in an enclosed location.
Their data also suggested that “the effect of temperature, up to 20 degrees [Celsius], was insignificant.” Therefore, a short holiday visit in the dark at room temperature is unlikely to produce significant changes in your cannabis. In fact, the paper showed some carefully prepared extracts are “reasonably stable for 1 to 2 years if stored in the dark at room temperature.” [1]
However, simply blocking the light from contacting plant material isn’t enough to completely prevent compound decomposition over more significant periods of time. A paper published in 2019 looked at varying storage conditions for cannabis products after four years and measured their cannabinoid levels every 100 days. The data showed that after four years, cannabis stored at room temperature—even in the darkness—had lost almost 100% of its delta-9-tetrahydrocannabinol (THC). [2]
The researchers found that freezing cannabis at -20° C was the best way to prevent cannabinoid degradation over time. [2] Cannabidiol didn’t really change over the timeframes and temperatures considered.
When it comes to humidity, however, it’s about more than just the compound profile of the plant. Controlling moisture levels is also a part of maintaining the quality of your cannabis over time. Researchers published a paper in 2019 that outlined an array of known pathogens and molds that can destroy cannabis, and they showed that high humidity was a key indicator of these types of problems. [3]
If you’re going on a short vacation, room temperature storage in a dark, non-humid environment will be enough to ensure a joyous return. For longer durations, the data is clear: freezing cannabis maintains optimal cannabinoid levels. Or, you could toss your product in the fridge for a dark, cool, controlled environment.
References
- Fairbairn, JW, et al. “The Stability of Cannabis and its Preparations on Storage.” J Pharm Pharmacol, vol 28, no. 1, 1976, DOI: 10.1111/j.2042-7158.1976.tb04014.x. [Times cited = 89 (GoogleScholar); Journal Impact Factor = 2.405]
- Zamengo, Luca, et al. “The Role of Time and Storage Conditions on the Composition of Hashish and Marijuana Samples: A Four-Year Study.” Forensic Science International, vol. 298, 2019, DOI: https://doi.org/10.1016/j.forsciint.2019.02.058. [Times cited = N/A; Journal Impact Factor = 1.947]
- Punja, Zamir K, et al. “Pathogens and Molds Affecting Production and Quality of Cannabis sativa L.” Frontiers in Plant Science, vol. 10, no.1120, 2019, DOI:10.3389/fpls.2019.01120. [Times cited = N/A; Journal Impact Factor = 4.298]
