Is Your Decaf Tested for Mold? Most Aren't.

Less than 2.0 micrograms per kilogram.

That is the amount of Ochratoxin A that Eurofins Central Analytical Laboratories detected in our green decaf coffee when they ran it through an LC-MS/MS assay in late October. Which is to say: none, at the limit of detection of an ISO 17025-accredited mycotoxin test. The four aflatoxins (B1, B2, G1, G2) came in the same way. Below detection.

That sentence took us about $400 and three weeks to be able to write.

What does the decaf in your kitchen come in at? You almost certainly do not know. Your roaster probably doesn’t know either. The industry has spent forty years selling coffee, decaffeinated and otherwise, without a requirement to disclose whether anyone has looked.

This is the post about what that means and why we decided to start.

What mycotoxins are, briefly

Mycotoxins are chemical compounds produced by certain molds when they grow on agricultural products. Coffee, peanuts, corn, dried fruit, spices, and tree nuts are the canonical risk categories. Coffee gets there honestly: cherries ripen on the tree in humid, warm climates, get pulped and fermented and dried in conditions that are exactly what some species of Aspergillus and Penicillium like. If post-harvest storage is sloppy, the molds settle in. If they settle in, they leave the toxins behind even after the mold itself is dead.

The toxins are heat-stable. Roasting reduces them. It does not eliminate them. A 2017 review in Comprehensive Reviews in Food Science and Food Safety summarized two decades of work on Ochratoxin A in coffee and concluded that roasting reduces concentrations on the order of 50-80%, depending on roast level and starting concentration. Useful, not magic.

There are two mycotoxin families that matter for coffee.

The two that matter

Ochratoxin A is the one coffee drinkers find first when they go looking. It is produced by Aspergillus ochraceus, A. carbonarius, and several Penicillium species. It is nephrotoxic in animal studies and is classified by the International Agency for Research on Cancer as possibly carcinogenic to humans (Group 2B). The European Union sets a regulatory limit of 5.0 micrograms per kilogram for roasted coffee and 10.0 micrograms per kilogram for green coffee. That is the strictest limit in any major regulatory regime. The United States does not have one.

How much typically shows up in real coffee? A frequently-cited 2003 study in Food Additives and Contaminants tested 116 retail coffee samples in Spain and found Ochratoxin A in 45% of them, with concentrations reaching 56 micrograms per kilogram in one sample. More recent surveillance work in the EU and in producing countries finds the average commercial sample tends to fall in the 0.2 to 8 microgram per kilogram range, with a long tail of contaminated outliers. The EU enforces the limit. Plenty of coffee in markets without enforcement does not get this scrutiny.

Aflatoxins are the other family. Produced by Aspergillus flavus and A. parasiticus, they are the most carcinogenic naturally-occurring substances known. The World Health Organization classifies aflatoxin B1 as Group 1 carcinogenic. The FDA enforces a 20 microgram per kilogram action level for total aflatoxins in human food. Coffee is a lower-risk category for aflatoxins than peanuts or maize, but contamination still occurs, particularly in coffee that has been improperly stored in warm humid warehouses.

If you are reading this and feeling alarmed, the right response is not panic. The right response is curiosity about what is actually in your cup, which is a question almost no coffee brand wants you to ask in those terms.

What the industry actually does

In the specialty coffee world, the answer to “do you test for mycotoxins” is usually some variation of “our supplier handles that” or “we work with high-quality farms” or “our cupping process catches off flavors.” All three statements may be true. None of them are a mycotoxin test.

The commodity coffee world is worse. Green coffee is bought and sold in lots that get blended, re-blended, and roasted across the country. Some lots have been tested somewhere upstream. Many have not. The bag on the supermarket shelf has no way to tell you.

There is no requirement in the United States to disclose decaffeination method on the package, much less mycotoxin testing results. The FDA does not require testing. The Specialty Coffee Association has voluntary standards but no enforcement mechanism. The result is a market where transparency is a marketing choice rather than a baseline.

Several brands in the “clean coffee” or “biohacker coffee” category have built their positioning on testing. Bulletproof started this conversation in 2014. The category has since expanded. Most of the loud claims, on close inspection, are not backed by published lab reports. Some are. The marketing language has run far ahead of the verification.

When we decided to take Heist seriously as a brand, the testing question was not optional. We are selling coffee to people who care about what they put in their bodies. Most of them already understand that “natural” and “premium” are words without much information in them. The only useful thing we can do is publish the work.

What we did

In October 2025, our roasting partner Lineage Roasting shipped a green coffee sample of our decaf to Eurofins Central Analytical Laboratories in New Orleans. Eurofins operates under ISO/IEC 17025:2017 accreditation with the American Association for Laboratory Accreditation (A2LA Certificate 2993.01). This is the international standard for testing laboratory competence. If a lab is accredited under 17025, the assays it reports have been validated, the technicians are documented, the methods are auditable, and the results are admissible as evidence in regulatory proceedings.

Eurofins ran two assays.

QA11H, Ochratoxin A in green coffee, LC-MS/MS internal method, ISO 17025-accredited. Liquid chromatography tandem mass spectrometry is the gold-standard analytical method for Ochratoxin A. It separates the compound from the matrix and identifies it by mass-to-charge ratio on two separate mass transitions. False positives at the detection limit are statistically negligible. The result on our sample, returned on the 31st of October: less than 2.0 micrograms per kilogram. Below the laboratory’s limit of detection.

QA21A, Aflatoxins, USP 561 Method 3 (Modified). This is the United States Pharmacopeia’s reference method for aflatoxin determination in herbal materials and food matrices. The result on our sample, returned on the 30th of October: all four aflatoxins (B1, B2, G1, G2) below detection at less than 5.0 micrograms per kilogram each. Sum of aflatoxins B1+B2+G1+G2: below detection.

The Eurofins report number is AR-25-QA-100167-01. If you want the raw paperwork, write to us and we will send it.

What those numbers mean in context

A few comparisons.

Our Ochratoxin A reading came in at less than 2.0 micrograms per kilogram. The European Union’s regulatory limit for roasted coffee, the strictest enforceable standard in any major market, is 5.0 micrograms per kilogram. The EU’s limit for green coffee is 10.0 micrograms per kilogram. Our green tested below detection on an assay calibrated four to five times tighter than the legal limit.

Our aflatoxin readings came in below 5.0 micrograms per kilogram total. The FDA action level for total aflatoxins in human food is 20.0 micrograms per kilogram. We are below detection at a quarter of the action level.

In the context of typical commercial coffee surveillance studies, where average Ochratoxin A concentrations cluster in the 0.2 to 8 microgram per kilogram range and outliers can stretch into the dozens, our sample is in the cleanest cohort.

What we cannot yet say honestly: “every batch is tested.” This was one batch, one sample. A first published result, not a rolling program. To make the every-batch claim we need every-batch data, and we are building that.

What’s next

Specialty coffee analytical labs like Eurofins are increasingly offering rolling per-batch programs that test every incoming lot for mycotoxins, pesticide residues, and heavy metals. That kind of ongoing testing is where we are headed. The goal is to publish every lot’s results, no exceptions, the same way we are publishing this one.

We also want to expand the test panel beyond mycotoxins. Pesticide residues, heavy metals, and residual caffeine on the decaf side are all categories where the industry has been allowed to mumble through the answer for too long. Transparent results, published openly, change what customers can ask for from every brand.

Until that program is live: one report, two assays, two negative results. The bar we are setting for ourselves.

What you can do as a coffee drinker

A short list, in order of value.

  1. Ask your roaster for their testing data. Most cannot give it to you. Some can. The ones that can are the ones to keep buying from.
  2. Look for ISO 17025-accredited lab reports, not “tested” claims. Anyone can write the word “tested” on a bag. The accreditation is the proof.
  3. Buy from roasters who publish results. Not a marketing page. Actual lab PDFs with sample IDs, methods, and dates.
  4. Be skeptical of “mycotoxin-free” as a phrase. No coffee is mycotoxin-free in the absolute sense. What you want is “below the detection limit on an accredited assay,” which is a precise and meaningful claim.
  5. Care more about the brand’s testing posture than the absolute number on any given test. A brand that tests every lot at 1.8 µg/kg is more trustworthy than a brand that tested once at 0.5 µg/kg and never again.

This is the kind of work the industry should have been doing for forty years. We are starting now.

If you want a decaf where the lab report exists and the numbers are public, our single-origin Blueprint is a good place to start. It is the highest cupping score in our lineup, sourced from the kind of farms where post-harvest handling is the obsession rather than the afterthought. We test the green before it becomes the bag.

Frequently Asked Questions

Is decaf coffee tested for mold? Almost no decaf coffee is independently tested for mold or mycotoxins, and the United States does not require it. Some specialty brands publish lab results voluntarily, but the practice is rare. Look for ISO 17025-accredited lab reports with sample IDs and methods listed.

What is Ochratoxin A? Ochratoxin A is a mycotoxin produced by Aspergillus and Penicillium mold species that can grow on coffee cherries during post-harvest storage. It is classified by the IARC as possibly carcinogenic to humans (Group 2B). The European Union enforces a regulatory limit of 5.0 micrograms per kilogram in roasted coffee.

Does roasting kill mold in coffee? Roasting reduces mycotoxin concentrations by approximately 50 to 80 percent, depending on roast level. It does not eliminate them. Mycotoxins are heat-stable compounds, which is why source quality and post-harvest handling matter more than roast level.

What does “mycotoxin-free coffee” mean? No coffee is mycotoxin-free in the absolute sense. The meaningful claim is “below the limit of detection on an accredited assay.” Heist’s green decaf tested below 2.0 µg/kg for Ochratoxin A and below 5.0 µg/kg for all aflatoxins via Eurofins, an ISO 17025-accredited lab.

Is decaf more or less likely to have mold than regular coffee? Decaf is not inherently more contaminated than regular coffee. The decaffeination process can either reduce or have no effect on mycotoxin levels, depending on the method. Water-process decaffeination is a wet process that may reduce some surface contamination, but the primary determinant is the quality of the green coffee going in.

What to read next

No Curfews is the editorial dispatch from Heist, a coffee company that thinks the second half of the day deserves better. We publish lab results, sources, and the occasional opinion. If this is the kind of thing you want in your inbox, join the list.