Cannabis can degrade significantly over time, leading consumers to question the safety and quality of aged flower. The central issue with smoking older cannabis involves a decline in potency and a risk of biological contamination. While reduced psychoactive effect is an inconvenience, inhaling unseen mold or bacteria poses a distinct health concern. Understanding the chemical and biological changes that occur as cannabis ages is necessary to make an informed decision about consumption.
The Chemical Transformation of Aged Cannabis
The primary psychoactive compound in cannabis, Delta-9-Tetrahydrocannabinol (THC), is chemically unstable and begins to break down when exposed to environmental factors. With exposure to light and oxygen, THC molecules undergo oxidation. This chemical reaction converts THC into a different cannabinoid known as Cannabinol (CBN).
This conversion results in a measurable reduction in the flower’s overall potency, as CBN is significantly less psychoactive than THC. CBN is often associated with more sedating effects, which is why older cannabis is sometimes reported to be more sleep-inducing. Studies show that under prolonged exposure to light and air, up to 30% of the original THC content can degrade into CBN.
Along with the breakdown of cannabinoids, the volatile compounds responsible for cannabis’s flavor and aroma also diminish. These compounds, called terpenes, evaporate or degrade due to improper storage. This loss leaves the aged flower with a diminished scent profile, often described as a muted, hay-like smell. While the aged flower may still produce an effect, its sensory experience and psychoactive profile will be significantly altered.
Primary Health Hazards: Mold and Pathogens
While chemical changes primarily affect quality, the greatest risk associated with older flower is biological contamination. Improper storage, especially with excess humidity, creates ideal conditions for the growth of mold, mildew, and various bacteria. Fungi such as Aspergillus, Mucor, and Cryptococcus are common contaminants found on improperly stored cannabis.
Inhaling mold spores from contaminated cannabis can lead to various respiratory problems, ranging from chronic coughing and wheezing to fungal infections in the throat and lungs. For healthy individuals, the reaction might be limited to nausea, vomiting, or irritation. Individuals with compromised immune systems or pre-existing lung conditions face a much greater hazard.
In vulnerable populations, inhaling certain fungal spores can lead to severe and even fatal infections. Mold produces toxic metabolites called mycotoxins, which are resilient and can survive combustion heat. Even if visible mold is burned away, inhaling these toxins can irritate the lungs and pose long-term health risks. Because contamination is a systemic issue, it is advised to discard any flower suspected of having mold, as removing the affected portion is not a reliable safety measure.
Identifying Degraded Cannabis
Assessing whether aged cannabis is still acceptable involves a simple sensory and visual examination. The appearance of the flower is the first indicator of degradation or contamination. Fresh trichomes, the tiny resin glands on the buds, appear translucent and crystalline, while mold often presents as a grayish-white, cotton-like or powdery coating on the surface.
Texture provides another clue; excessively dry flower will crumble easily into dust when handled, indicating a loss of moisture and terpenes. Conversely, a bud that feels spongy, unusually sticky, or damp may retain too much moisture, which encourages mold growth. Breaking a bud open allows for inspection of the interior, where mold may begin to grow unseen.
The smell of the cannabis is a strong diagnostic tool. While aged but uncontaminated cannabis may develop a mild, hay-like scent from terpene loss, any sharp or unpleasant odors are a clear warning sign. A musty, mildewy, or ammonia-like smell indicates the presence of mold or bacterial growth. Any such odor or the presence of fuzzy spots should lead to the immediate disposal of the product.