California’s Department of Cannabis Control (DCC) issued a voluntary recall notice for multiple Top Shelf Cultivation flower products in early 2025, citing the presence of Aspergillus spp. contamination. The recall affected a wide range of flower batches distributed across the state’s licensed retail network.
Aspergillus: The Persistent Threat
Aspergillus is a genus of mold that can cause aspergillosis, a serious lung infection particularly dangerous for people with weakened immune systems. California mandates testing for four specific Aspergillus species in cannabis products, and a single positive result is enough to trigger a mandatory recall.
What makes Aspergillus so challenging for cultivators is its ubiquity. The mold thrives in warm, humid environments and can colonize cannabis plants at any stage from cultivation through post-harvest drying and curing. By the time a product reaches a licensed testing lab, contamination may already be widespread across an entire harvest batch.
California’s Growing Recall Problem
The Top Shelf Cultivation recall was not an isolated event. Throughout 2025, California saw a significant uptick in mold-related product recalls, with multiple brands facing costly pullbacks due to failed Aspergillus testing. The state’s DCC maintains a public recalls portal, and cultivators would do well to review it regularly to understand the scope of the problem.
Industry observers note that California’s testing requirements are among the most stringent in the nation. While this protects consumers, it also means cultivators face a higher bar for compliance. A batch that might pass in a less regulated state can still fail in California.
What Cultivators Should Learn
Every Aspergillus recall points back to the same root cause: contamination that wasn’t eliminated before the product went to market. Third-party testing is the final checkpoint, not the solution. Cultivators who rely solely on passing a lab test are playing defense in a game where the offense wins every time a recall happens.
Post-harvest decontamination that targets mold and spores at the microbial level is the most reliable way to reduce Aspergillus risk before product ever reaches a testing lab. California’s recall wave should be a signal for the entire industry to invest in preventive solutions.
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