Do a quick search for how to dry cannabis and welcome to a world of differing—and sometimes even conflicting—information. Some good, some flat-out incorrect, and others so sticky, they’ve been passed down from generation to generation.
From “how to stop bud rot when drying” to “how to prevent mold when drying weed” . . . the search results are sometimes hard to sift through to figure out what works best when drying cannabis at the commercial level.
And there’s good reason for the interest. After all of that hard work and human-hours spent growing and harvesting your plants, it’s important to understand the tenets of drying for many reasons, including:
- How to prevent mold when drying weed
- How to prevent bacterial microbe growth
- How to stop bud rot when drying your plants
Getting Into the Weeds of Drying
Before we can jump into some of the most successful tips and tricks we’ve picked up, we’ll need to go over a few terms. Let’s start with a water activity definition, and how it applies to the science behind how to properly dry marijuana. Then we can talk briefly about moisture content and how these two forces work together.
Two Sides, Same Science
Growers, get to know these terms if you want to know how to prevent mold when drying weed. Low humidity cannabis exists on a spectrum and the mechanisms that pull porous materials (like cannabis bud) toward dryness or wetness work together as intensive and extensive variables. Their names: Moisture Content and Water Activity.
Water Activity (aw)
Cannabis processors probably already know about the concept of water activity, they just speak about it as relative humidity (RH). Relative humidity is measured in air and expressed on a scale from 0-100%. Water activity is the same concept applied to a porous medium like food, pharmaceuticals, or—you guessed it—cannabis, and is expressed on a scale from 0-1.00.
Water activity is the energy state of water in a system. The “system” in this case, is cannabis bud. This energy state can be affected by both chemical and physical bonds, which is crucial to understand when processing and drying cannabis.
Moisture Content (w)
Also known as “water content,” this is the percentage of a product’s weight that’s composed of water. It can be reported on either a wet or dry basis. The basis should always be specified.
But this is just the tip of the trichrome. There are many other physical forces that play a part in how water activity changes, including hydrogen bonds, capillary action, and Van der Waals-London Dispersion Forces. These are known as “matric effects.” To go deeper into the science, check out The AROYA Complete Guide to Drying Cannabis ebook (coming soon!).
Tech and Tools to Help Prevent Mold
Just like with food, there’s a line cultivators and processors must walk to ensure their cannabis ends up at the right end of the water activity scale and is safe and enjoyable to consume.
When you want to know how to prevent mold when drying weed, you’re going to need something more. You’re going to need the tools to help you accurately measure the moisture content of your cannabis. In short, you’re going to need a weed curing machine. Or a sensor, if you want to be exact about it 😉.
In our years in the drying biz, we’ve found that chilled-mirror dew point sensors (no, it’s not for freeze-drying weed, if that’s what you’re wondering) are faster and more accurate than other subjective tests. If you’re relying on methods like the snap test, it’s virtually impossible to really know if your cannabis is dried to the correct level.
Luckily, this is 2022. We have the tools to give us more insights into the moisture content inside drying bud. Thanks to old science and new sensors, you’ll be much more likely to consistently dry your bud to the right level, with no destruction of your sample in the process.
The AQUALAB is able to give cannabis cultivators one-minute readings that are ten times as accurate and is based on ISO-18787. When you’re ready for more accurate readings that can help you dry your bud to the perfect level every time, hit us up for a demo.
Still Have Questions About Drying?
Let’s air ‘em out together. Get to know the basics with the The AROYA Complete Guide to Drying Cannabis ebook.
Or, if you have a more general question about cannabis crop steering, you may find our educational videos have the information you’re looking for. And we’re always here to help you schedule a demo to start working with some of the most intelligent cannabis drying technologies available to commercial cannabis growers today.
Photo credit: Gaetano Sferrazza on Unsplash