Written by Joshua Sosin

Cannabis is a natural product, which means it’s subject to all kinds of environmental factors — including mold.

One of the types of mold that can develop on cannabis is Aspergillus. If you’ve ever heard horror stories about contaminated weed, this name might sound familiar.

Let's take a look at what you need to know about this type of mold, how it grows on cannabis plants, and how to avoid it by choosing weed from a reputable source.

Learn more about mold on weed and how to avoid it from the Mood Blog.

Table of Contents

• What Is the Aspergillus Species of Mold?

• Why Does Aspergillus Grow on Cannabis Plants?

• How to Identify Aspergillus on Cannabis Flower

• What Happens If You Consume Weed With Mycotoxin Contamination?

• How to Prevent Fungal Spore Contamination

• The Importance of Third-Party Testing for Cannabis Consumers

• What to Do If You Suspect Your Cannabis Is Contaminated

• Stay Safe With High-Quality Weed From Mood

What Is Aspergillus?

Aspergillus fumigatus is a type of mold that includes several different species, some of which can be harmful to humans.

While Aspergillus is found everywhere in nature, including soil, air, and plant material, it becomes a serious problem when it contaminates food or cannabis. Certain strains of Aspergillus produce mycotoxins, which can have potential health risks when inhaled or ingested.

For cannabis users, Aspergillus is especially concerning when it grows on flower that’s meant to be smoked or vaped. Unlike ingesting moldy food (which the stomach acid can often neutralize to some extent), inhaling mold spores can introduce them directly into the lungs, leading to potential respiratory issues.

Why Does Aspergillus Grow on Cannabis?

Mold thrives in warm, humid environments, two factors that also play a big role in cannabis cultivation and storage. Aspergillus mold can take hold at several points in the production process:

• During Cultivation: If cannabis is grown in overly humid conditions without proper airflow, mold spores can settle and spread on the plant.

• During Drying and Curing: If cannabis isn’t dried correctly or cured in a controlled environment, excess moisture can lead to mold growth.

• During Storage: If stored in airtight, humid conditions, cannabis can develop mold over time, especially if it wasn’t properly dried beforehand.

Because Aspergillus spores are already present in the air, they don’t need much to start growing. High humidity and poor ventilation create the perfect storm for contamination.

How to Identify Aspergillus on Cannabis

Spotting Aspergillus on cannabis isn’t always easy, but there are a few signs to watch out for:

• Visible Mold: Aspergillus often appears as a powdery or fuzzy coating on cannabis, ranging in color from white to green, yellow, or even black.

• Unusual Smell: Moldy cannabis tends to have a musty, damp, or even slightly sour odor. If your weed smells off, it’s best to err on the side of caution.

• Texture Changes: If your bud feels unusually damp, spongy, or clumpy, mold might be present.

What Happens If You Consume Contaminated Weed?

Smoking or vaping Aspergillus-contaminated cannabis can be dangerous, especially for people with weakened immune systems or respiratory conditions. Inhaling mold spores can lead to lung infections, allergic reactions, and, in severe cases, a condition called aspergillosis, which can cause breathing difficulties and other serious health issues.

Even if you don’t have preexisting health concerns, consuming moldy cannabis can still result in irritation and discomfort. That’s why it’s a must to make sure your weed is clean and safe before lighting up.

Aspergillus Prevention: How To Avoid Contaminated Cannabis

The good news? There are several steps you can take to minimize the risk of mold contamination:

• Buy From Trusted Sources: Reputable dispensaries and online retailers like Mood prioritize quality control and lab testing to make sure all products are mold-free.

• Check for Third-Party Testing: Always look for a Certificate of Analysis (COA) to confirm your cannabis has been tested for mold and mycotoxins.

• Store Your Cannabis Properly: Keep your weed in a cool, dry place. Use airtight containers with humidity control packs to maintain optimal moisture levels (55-62% relative humidity is ideal).

• Inspect Your Buds Regularly: Before consuming, check your flower for any unusual smells, textures, or visual signs of mold.

The Importance of Third-Party Testing

Because Aspergillus contamination isn’t always visible, third-party testing is one of the best ways to ensure cannabis safety. Lab tests screen for microbial contaminants, including mold and mycotoxins, giving consumers peace of mind that their product is clean and safe.

At Mood, we take testing seriously. All of our products undergo rigorous third-party lab testing to ensure they meet safety standards. You can access COAs for all of our products on the Mood Shop website.

What to Do If You Suspect Your Cannabis Is Contaminated

If you think your weed might be moldy, do not smoke it. Here’s what to do instead:

1. Inspect It Closely: Look for signs of mold, like unusual colors, textures, or a musty smell.

2. Check the Source: If you purchased from a dispensary, contact them to report the issue and see if they offer refunds or exchanges.

3. Dispose of It Safely: Moldy weed isn’t worth the risk. It’s best to throw it away rather than try to salvage it.

4. Avoid DIY Fixes: Some people suggest microwaving or baking moldy cannabis to “kill” the mold, but this doesn’t remove harmful mycotoxins. Contaminated weed should always be discarded.

Stay Safe With High-Quality Weed From Mood

Aspergillus contamination is a serious issue, but it’s also preventable. By purchasing from trusted sources like Mood, and storing your cannabis properly, you can reduce the risk of mold growth and keep your stash fresh and safe.

At Mood, we’re committed to providing high-quality, lab-tested cannabis products you can trust. Browse our full selection of cannabis flower now and use the code "FIRST20" to get 20% off your initial order.