What's Actually In Your Coffee?

We Asked Our Producers About Mold, Mycotoxins, and Quality Control

A customer question sparked a conversation across continents — here's what we learned.

Recently we received an email from a customer asking a question we've been seeing more and more: Does Treeline test for mold or mycotoxins in our coffee?

It's a fair question, and an important one. While we thought we had a good handle on the answer, we decided it was time to dig a little deeper.

We reached out to over a dozen of our partners who touch every point of our supply chain and asked them directly. What came back was a rich, honest, and genuinely educational conversation that we think every curious coffee drinker deserves to read.

So here it is.

First, What Are Mycotoxins?

Mycotoxins are toxic compounds produced by certain molds. In coffee, the one that comes up most often is Ochratoxin A (OTA), which can develop when coffee cherries are improperly dried, stored in humid conditions, or mishandled in transit.

Here's the important context: OTA in coffee is a real and legitimate topic — but it's not the existential health threat that some corners of the internet make it out to be.

The European Union tightened its OTA limit for roasted coffee in January 2023, dropping it from 5.0 µg/kg to 3.0 µg/kg based on updated science. The U.S. currently has no federal OTA limit for coffee — though a recent FDA rule now requires LAAF-accredited laboratories be used when mycotoxin testing is required. The National Coffee Association (NCA) has noted that, despite growing consumer interest, "there is no evidence to suggest that OTA is a problem in coffee" when standard industry practices around moisture control and sensory evaluation are followed.

Where Mycotoxins Actually Come From — and How They're Prevented

Every single partner we reached out to pointed to the same root cause: moisture. OTA is produced by Aspergillus and Penicillium molds, and those molds need available water to grow. Control moisture, and you control the risk.

At La Gloria Estate in Panama, owner Norberto (aka El Jefe) has been overseeing every step of processing on his farm since 1984, with coffee trees that have been producing for over 60 years. His process is meticulous: only ripe, red cherries are hand-picked daily; coffee is wet-processed and then dried in indirect-fired cylindrical dryers to exactly 11% moisture; and finished parchment is stored in polypropylene sacks with Ecotac moisture-barrier bags in a temperature-insulated warehouse. Norberto put it plainly: "Ochratoxin is a toxin produced in coffee when the parchment bean drying process is not handled properly." His farm's entire workflow is built around making sure that never happens.

The team at IAC (NKG Coffee), one of our green coffee importers, echoed this at the trade level. They monitor moisture content before containers are sealed (Arabica must be below 12%), again on arrival at the destination warehouse, and again at their headquarters lab. If a sample tests higher than expected, they don't condemn the whole batch — they resample with multiple stick samples across bags and run a composite second analysis. It's a careful, methodical approach.

Samaria Coffee in Colombia (the main ingredients in our Blackbeard espresso), sourced directly from family farms in the Andes, takes a similar approach. Daniel Osorio described their controls: selective cherry picking, flotation to remove defects, controlled fermentation, and proper drying and storage. Samaria is FDA registered and works with supply chain partners who maintain food safety standards throughout. While they don't conduct routine third-party mycotoxin testing on every lot, they can coordinate specialized testing for wholesale partners on request.

What the Specialty Coffee Standard Actually Means

Several of our partners made a point worth dwelling on: specialty coffee processing standards are, by design, the same practices that prevent mold and mycotoxin development.

Maddy at Onyx Coffee (Importers) framed it well: the rise of "mold-free coffee" as a marketing term has unintentionally created the perception that coffee needs a special certification to be clean or safe. But if coffee is truly being sourced and evaluated at specialty standards — with attention to moisture, storage, sorting, and traceable supply chains — mold shouldn't be a prevalent issue in the first place. The coffees where masking of defects is more plausible, she noted, are heavily flavored or pre-ground conventional products, not transparent specialty offerings.

 

Third-Party Testing: What It Does and Doesn't Tell You

A few specialty brands, like Purity Coffee (U.S.) and Exhale (U.K.), have built their businesses around third-party lab testing as a core differentiator. Nico at Mountain Harvest put this in helpful perspective: "It does not mean that every other coffee on the shelf is contaminated. It means they have chosen to verify what good supply chains are already doing." Like other certifications, that extra validation can be a useful shortcut for consumers who aren't visiting farms and mills directly.

Mountain Harvest itself is USDA Organic certified, which includes third-party lab testing as part of the annual external audit — so there is an independent paper trail behind that seal. Norberto at La Gloria Estate, meanwhile, participated in a formal research project with the Technological University of Panama (UTP) and their Laboratory of Industrial Analysis and Environmental Sciences (LABAICA), establishing a chemical "fingerprint" of La Gloria's green and roasted coffee. Results from that study are forthcoming and we'll share them when available.

None of our other partners currently conduct routine third-party mycotoxin testing — but all of them described robust process controls, and several noted they're open to reevaluating as the industry evolves and better standards emerge.

What This Means for You as a Treeline Customer

We don't currently conduct routine third-party mycotoxin testing on every coffee we carry. What we do is work intentionally with partners who take the upstream practices seriously — the drying, the moisture monitoring, the storage, the short and traceable supply chains.

Coffee is an agricultural product, and "zero" of anything isn't a meaningful guarantee for any natural food. But well-produced specialty coffee, handled with care from cherry to cup, is about as far from a mold risk as coffee gets.

We're grateful to every partner who took the time to respond to our questions — and thank you to all of our customers who trust us and get curious with us!

Have more questions about how we source our coffee? We'd love to hear from you at natalie@treelinecoffee.com