Marijuana Mold Prevention and Proper Storage

Identifying mold on cannabis isn’t as easy as spotting it on other food products. Mold on cannabis can resemble white trichomes or be hidden in the crevices of the bud. Keeping your stash free from mold is essential to having a safe experience. Learn how to prevent marijuana mold.

What is Mold?

Mold is a type of fungal growth that thrives in damp environments and decaying organic matter. Different species can have different colors. In optimal environments, mold releases tiny airborne spores that help it reproduce new mold colonies.

What Causes Marijuana Mold?

Mold can wreak havoc on cannabis through every stage of its life cycle, from its cultivation phase to storage. In general, cannabis quality can be affected by heat, light, air, and moisture. All of these can contribute to an environment where mold can develop.

Here are the main causes of mold in cannabis:

• Poor airflow
• High humidity
• Temperature fluctuations

Is It Safe to Smoke Moldy Cannabis?

Smoking moldy cannabis is not recommended. Will it kill you? Probably not. If you’re healthy, smoking moldy cannabis will most likely not make you feel sick, although that does not account for the risks of smoking.

Moldy cannabis can taste harsh and cause a coughing fit, nausea, or even vomiting, but usually nothing more than that. However, if you have a mold allergy, it can cause sinus or lung inflammation. Watch out for the following symptoms:

• Congestion
• Wheezing
• Drainage
• Sinus pain

Smoking moldy cannabis when you have a compromised immune system or respiratory conditions can cause severe health consequences. For instance, Cryptococcus, Aspergillus, and Mucor fungi can lead to severe and even lethal central nervous and respiratory system infections.

Signs of Marijuana Mold

Always look for signs of mold, even if you’ve purchased your buds from legal suppliers. Lab testing is the most accurate way to identify the presence and concentration of mold. 

A low-powered microscope can help you tell the difference between mold and trichomes. Trichomes are the sticky, translucent, or sometimes amber-colored resin glands on the buds. They are also found in lower concentrations on the stems and leaves.

A black-light can make mold appear a yellow or green color.

Signs of mold on cannabis:

• Dampness
• White or gray fuzz
• Specks of dry white or gray powder
• Stale, musty, and foul smell

Can You Remove Marijuana Mold?

It’s not as simple as removing mold from cannabis. If you’re on the last of your stash, you may just want to cut off the moldy portion and use the rest, but you may still be consuming mold that isn’t visible to the naked eye. Don’t take the risk of smoking moldy cannabis.

How to Prevent Marijuana Mold

Storage is a critical part of keeping your cannabis fresher for longer and preventing mold. As mentioned above, cannabis exposure to heat, humidity, light, and oxygen can create an optimal environment for mold to thrive.

Do Not Store Cannabis in the Refrigerator or Freezer

Generally, storing cannabis in a refrigerator or freezer is not recommended because of the temperature and humidity fluctuations that can occur when you open and close the fridge or freezer door. Cannabis should be stored at temperatures of about 70º F.

Store Cannabis in an Airtight and UV-Protected Container

Glass jars are the classic storage option for cannabis plant material (bud, trim, stems, etc.) and the best way to prevent mold formation. Mason jars or jars specifically designed for cannabis storage can reduce exposure to oxygen and moisture, preventing a damp environment.

Check out our list of the 7 best cannabis glass jar options to keep your buds fresh

Store Cannabis in a Cool, Dry, and Dark Place

Moisture, heat, oxygen, and direct exposure to light are all elements of the ideal environment for mold. Sun or artificial light exposure can speed up your bud’s natural degradation process and dry it out. A damp environment can cause an excess of moisture if a poorly sealed container.

To keep your cannabis fresh for a long time, keep it in a dry and dark area, like a pantry or closet, as long as it does not experience high temperatures.

Consider the Relative Humidity

The optimal relative humidity (RH) for cannabis is 59-63%. Higher humidity levels can lead to a damp environment where mold can thrive.

Humidity packs can regulate moisture levels within a container to achieve an optimal RH. A blend of salts and water removes or adds moisture to the environment as needed. Keep in mind that humidity packs must be replaced about every two months.

If you’re serious about humidity control and have extra cash to spare, humidors designed for cannabis storage are made from high-quality wood and protect buds and other cannabis products from moisture, light, and oxygen.

Final Thoughts on Preventing Mold on Weed

Moldy cannabis can ruin a good time. However, there are ways to identify mold's smell, look, and taste. Checking cannabis for mold before consuming it, especially for those with weak immune systems, is recommended.