Coffee, Mold, and Marketing Claims — Understanding the References
Aug 21, 2026
Every so often, ads circulate claiming that “studies show coffee contains mold, chemicals, or pesticides.” These statements often sound scientific but rarely include citations or context. And to be clear from the start: this post may not change anyone’s mind. Coffee‑and‑health debates can go on endlessly, and I encourage everyone to do their own research and come to their own conclusions. If you are looking for an argument, this is not the place where you will be able to get one underway.
My goal here is simply to state our position clearly, explain how specialty coffee actually handles these concerns, and offer transparency about the safeguards built into the supply chain.
Why Mold Comes Up in Coffee Conversations
Mold and mycotoxins can occur in agricultural products, including coffee. That’s true. But specialty coffee has multiple safeguards in place long before beans reach a roaster. Modern drying standards, climate‑controlled storage, importer quality systems, and sensory evaluation all work together to prevent mold from becoming a meaningful issue.
The problem isn’t the topic — it’s how some brands use it.
A Helpful Video Overview
If you prefer a clear, balanced explanation, James Hoffmann has an excellent breakdown of mold and mycotoxin claims — including lab‑testing coffees marketed as “healthy” or “mold‑free.” His findings align with what we see in the specialty supply chain:
- negligible heavy metals
- no detectable ochratoxin in tested coffees
- no evidence supporting fear‑based marketing
His video is a good primer, but let’s go deeper into the actual science.
1. What FDA and EFSA Actually Say About Mycotoxins in Coffee
Both the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) monitor mycotoxins such as ochratoxin A (OTA) and aflatoxin in foods.
Coffee is not considered a high‑risk product.
EFSA’s 2010 scientific opinion states:
“Coffee contributes minimally to overall dietary exposure to ochratoxin A.”
FDA’s guidance on mycotoxins similarly notes that coffee is not among the commodities of highest concern.
Typical levels found in coffee are far below safety thresholds.
Modern peer‑reviewed studies consistently show:
| Mycotoxin | Typical Range in Specialty Coffee | Regulatory Limit (EU) | Notes |
|---|---|---|---|
| Ochratoxin A (OTA) | 0–2 µg/kg | 5–10 µg/kg | Most specialty lots test at or near 0 |
| Aflatoxin | 0–0.5 µg/kg | 10–20 µg/kg | Rare in properly dried coffee |
These limits exist for all foods — not because coffee is uniquely unsafe.
2. Older Studies Don’t Reflect Today’s Specialty Supply Chain
Some papers from the 1990s and early 2000s examined mold growth in poorly stored green coffee:
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high humidity
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long storage
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no climate control
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moisture levels above ~13.5–14%
Those conditions simply don’t reflect modern specialty practices.
Today, specialty coffee is:
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dried to 10–12% moisture, with some lots at 13% still considered safe
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stored in climate‑controlled warehouses
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shipped in GrainPro or Ecotact liners
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monitored at multiple points in the supply chain
Modern studies confirm that these conditions do not support mold growth.
3. The “Mold‑Free Coffee” Narrative Started as Marketing
The idea that coffee is “full of mold unless specially tested” did not originate in peer‑reviewed science. It began with:
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early wellness blogs
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single‑sample tests
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non‑validated lab methods
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marketing campaigns built around fear
These posts often cited outdated studies or misinterpreted regulatory guidance. The narrative spread because it created a niche: “clean coffee” vs. “everything else.”
When you see claims that “only one brand” is mold‑free, it’s worth remembering that this narrative began as a marketing angle — not a scientific discovery.
4. What Real Safeguards Look Like (With Actual Numbers)
Specialty coffee has multiple layers of protection built into the supply chain. Here are the actual practices used by reputable importers across the industry:
Moisture Control
Green coffee is typically dried to 10–12% moisture, but values up to 13% are still within normal specialty ranges and not considered dangerous.
Mold growth becomes a realistic risk only when moisture rises above 13.5–14%, especially if combined with:
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high ambient humidity
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warm storage conditions
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long storage times
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unlined jute bags
Modern specialty practices are designed specifically to avoid those conditions.
Importer Practices (generalized)
Prominent specialty importers use a combination of preventive controls:
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Moisture testing at offer, pre‑ship, and arrival
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Target moisture ≤ 12.5–13% depending on origin and processing
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GrainPro/Ecotact liners to prevent moisture migration
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Climate‑controlled warehouses for stable temperature and humidity
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Supplier audits under FSVP/HACCP‑style quality systems
These practices are standard across the specialty industry and are designed to prevent the conditions under which mold can develop.
Sensory Screening
Moldy coffee has a distinct sensory signature:
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musty
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earthy
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phenolic
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“basement” aroma
These defects are easily detected and rejected during cupping.
Regulatory Oversight
FDA and EFSA monitor food safety continuously. Coffee is not flagged as a high‑risk commodity.
5. Detectable vs. Present vs. Harmful — A Critical Distinction
Mold‑free marketing often blurs three different concepts:
Detectable
A lab can detect extremely small amounts — sometimes parts per billion.
Present
A compound may exist at a trace level but be irrelevant to health.
Harmful
A compound must exceed regulatory thresholds to pose risk.
These are not interchangeable.
For example:
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A coffee with 1 µg/kg of OTA is detectable
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It is technically present
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But it is far below the EU limit of 5–10 µg/kg
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And EFSA considers coffee a minimal contributor to dietary exposure
This is why “zero mold” claims are scientifically meaningless. Zero is not a realistic or necessary standard in food science.
The Bottom Line
Clean, safe coffee isn’t a rare exception. It’s the baseline.
At Cairn Coffee Roasters, we don’t rely on fear‑based claims or vague references. We rely on trusted partners, responsible sourcing, and the same stewardship‑driven approach that guides everything we do.
Our goal is simple: to roast coffee you can enjoy and trust — without the marketing noise.
If you’d like to explore this topic further or have questions about how coffee is processed, stored, or evaluated, we’re always happy to talk. Transparency is part of our craft.
References & Further Reading
EFSA — Scientific Opinion on Ochratoxin A (2010) https://www.efsa.europa.eu/en/efsajournal/pub/1620
FDA — Mycotoxins in Food https://www.fda.gov/food/chemical-contaminants-food/mycotoxins
Ochratoxin A in Coffee: A Review (2017) https://doi.org/10.1080/10408398.2015.1077197
Mycotoxin Occurrence in Specialty Coffee Supply Chains (2019) https://doi.org/10.1016/j.foodcont.2019.01.015
James Hoffmann — Coffee, Health & Mycotoxins (YouTube) https://www.youtube.com/watch?v=7Z6k8P8z6bU
Edited 8/23/2026 to update reference links and introduction paragraph.