There are many elements to consider when properly curing and storing your cannabis. One of the most crucial considerations is managing the relative humidity (RH) of the plant material while it is stored in an airtight container. Having too much moisture will increase the risk of contamination by mold or mildew, while having too little moisture will cause the trichomes to dry out, becoming brittle, harsh, and less effective as the essential oils that carry the cannabinoids and terpenes slowly degrade.
Luckily, there’s a solution that avoids the difficult balancing act of monitoring the ambient humidity of your climate, maintains the ideal RH, and gives you a powerful tool to give your cannabis the best possible cure.
What is Ambient Humidity?
Ambient humidity is what’s happening outside your container of cannabis. It could be your bedroom, the trunk of your car, or the outdoors. In air conditioned homes, the humidity is usually 20-30% because the AC scrubs moisture out of the air. In a heated home, the humidity will often be even lower as the furnace scrubs much of the ambient humidity.
In the time it takes to open and prepare cannabis for consumption, the flower can lose a detectable amount of moisture. Without a proper way to monitor and adjust humidity in your container, the cannabis will dry over time.
Using humidity control products like Boveda 62 in the container allows you to quickly replace the lost moisture both in the air and in the plant, so the cannabis is the same original quality every time. Some would even make the case it gets better with age, like wine or cigars.
The RH “Sweet Spot”
Humidity control packs can monitor ambient humidity and add or remove moisture to deliver a precise RH, giving your cannabis the optimal moisture content and keeping it true to its original form. For example, the Boveda 62, developed after repeated requests from cannabis aficionados to create a pack that held a lower RH, keeps your buds at the perfect 62% RH level.
To determine the best RH for cannabis, we hired a third party laboratory to do a moisture sorption isotherm on a single strain of cannabis. A moisture sorption isotherm test applies a wide range of humidity levels to an item and determines an RH range in which the properties of the item doesn’t change. For the strain of cannabis the lab tested, 59-63% RH showed to be ideal.
In the same way nature has gifted the world cannabis, it gifts us the natural salts that provide the key to balancing RH levels. Different salt compounds hold a varying range of moisture, which makes it crucial to source a salt that stabilizes moisture content at an ideal 62%.
Many who prefer vaporizing their cannabis are finding they favor even lower humidity levels, such as the 54%. Personal preference can also dictate your ideal RH “sweet spot,” with elements like plant density and personal taste being the deciding factors.
How Does RH Affect the Curing, Drying, and Storage of Cannabis?
If you want the best possible cure, you need to store cannabis in an environment with stable RH within the ideal range. The ambient humidity isn’t much of a concern, because Boveda responds to conditions inside the container, absorbing or releasing moisture to maintain the ideal 62% inside.
From there, your major concerns are temperature and light. Boveda adjusts the humidity based on temperature changes, but cannabis should always be kept away from high temperatures to avoid decarboxylation or activating the precious cannabinoids. And as widely recommended throughout the cannabis industry, always store you cannabis in a cool dark place.
While Boveda is effective at removing excess moisture, growers should still dry cannabis using their traditional methods, and when the branches feel close to their target moisture content, put the buds in containers with Boveda to help adjust the RH to the proper range for cannabis.
some info from: Leafly