How Cannabis Moisture Content is Measured
Cannabis is susceptible to getting moldy or developing contaminants just like any other food or drink your customers may buy. To help minimize the chance of that happening, cultivators and manufacturers should, and are often required, to check that moisture content is within an optimal range before the product can be sold to customers.
In this blog, you will learn:
Why, and how, moisture content impacts cannabis product quality
How moisture content is measured
If New Jersey licensed cannabis cultivators and manufacturers are required to test for moisture content
What is moisture content in cannabis?
Moisture content refers to the total amount of water contained within a cannabis product, and particularly as it pertains to cannabis flower. This is measured and expressed as a percentage of the total weight of the tested sample. In simple terms, the higher the moisture content, the greater the chances that the cannabis flower is at risk for developing mold and other contaminants.
Why moisture content in cannabis matters
Moisture content is crucial for a cannabis product’s quality and integrity, in addition to being a regulatory compliance component in many states. Here is how moisture content affects cannabis:
Moisture content directly corresponds to product quality. Excess moisture can feed contaminant growth. However, too dry a flower is brittle and not as potent. A “just right” moisture content keeps contaminants at bay while offering the desired cannabis consumption experience.
It can impact phytocannabinoid content of flower. Cannabis flower with too low moisture content will have fragile trichomes, where most of the plant’s phytocannabinoid and terpene content can be found. This affects the potency of the final product, as well as its terpene-driven aroma.
Improved shelf stability. Excessive moisture content influences how quickly cannabis flower can spoil. When cannabis products contain the right moisture levels, they can be safely stored until the expiration date listed on the package.
It is required. Moisture content checks are a regulatory requirement in many states with a medical cannabis program or an adult use cannabis program. While the precise moisture content level varies by state, the test itself is a must. Additionally, some states only require that cannabis flower is tested for moisture content, while some states expand this requirement to cover other types of cannabis products.
How cannabis moisture content is measured
Cannabis moisture content is measured by calculating the difference in a sample’s weight before and after drying it. There are two main ways to conduct this test.
Loss on drying: This method involves drying the sample until it reaches a moisture content of zero percent. The weight of the sample is recorded before and after drying. Moisture content is calculated based on the weight change.
Bench top moisture analyzer: Like loss on drying, this machine also slowly dries the cannabis sample. However, it automatically records product weight during the process, reducing human error. These machines are often utilized when testing food and drink for moisture content.
Is there an ideal moisture content level?
Yes. Moisture content levels typically fall between 6% and 15%, but ideal levels are between 6% and 9%. Some cultivators and manufacturers believe that as high as 12% is fine without sacrificing product integrity. Moisture content levels also may vary by cultivar, the grow techniques preferred by the cultivator, and the climate in which the cannabis is grown.
Is moisture content testing required in New Jersey?
New Jersey’s current interim cannabis testing rules require that moisture content is measured in raw plant material. These interim requirements are based upon Maryland’s testing standards for medical cannabis. This requirement may change as the New Jersey Cannabis Regulatory Commission (CRC) revises and finalizes guidelines for the emerging adult use cannabis industry.
Moisture content vs. water activity: What’s the difference?
Moisture content (also sometimes called water content) refers to the total amount of water in a cannabis product. However, not all moisture contributes to contaminant growth. For that measure, scientists turn to the water activity of the product.
Water activity (Aw) is a more specific measurement that checks the availability of that water content to feed the growth of contaminants like mold. Water activity is measured by comparing the vapor pressure of the water contained within the product to the vapor pressure of distilled water when subject to the same conditions. The higher the water activity measurement, the more "free water" is available for microbes to utilize and proliferate.
Water activity is considered a more accurate measure of determining if a cannabis product may become contaminated. That is because high water activity means that water is free to be used as a food source or support chemical and enzymatic reactions that can spoil or contaminate the cannabis product.
Water activity measurement is expressed on a scale of 0.00 to 1.00. The standards organization ASTM International has recommended an Aw measurement between 0.55 and 0.65 for most cannabis products.
Moisture content testing with True Labs for Cannabis
The right moisture content in your cannabis product ensures that what you are selling stays fresh and its phytocannabinoid and terpene content remains stable. At True Labs for Cannabis, our third-party laboratory services provide honest, verified, and reliable data so you can ensure you are providing the safest possible products to your customers. In addition to moisture content and water activity testing, we offer many other types of tests that check for product potency, homogeneity, mycotoxins, and more. Based in East Hanover, we serve licensed cannabis cultivators and manufacturers throughout New Jersey. Learn more by contacting our leadership.