In the early 2000’s, the Food and Agriculture Organization (FAO) of the United Nations collaborated with the International Coffee Organization (ICO) and the Common Fund for Commodities (CFC) to address an emerging public health concern with coffee: the presence of a naturally occurring toxin produced in the processing of coffee called OTA or ochratoxin-A1. What was ultimately concluded was that attempts to control the growth of mold or fungus at origin during processing would limit the proliferation of this toxin to a levels of negligible concern2. The study that resulted outlines various ways of measuring this growth and attempting to control it. This is a rather cursory summary of the study, and purposefully so, as there is arguably more interesting content when we consider the precedent set by this study, and other studies that came out of it. With the Specialty industry being one largely populated by philosophy undergrads, musicians, and other intelligent misfits of various creed – scientific research can at times seem too pedantic for our palates. But insofar as it can pertain to a language that we work to build and claim ourselves to be the purveyors of (quality, that is), it might be worth reaching out, or at the very least, listening in. Using this study as a jumping off point, we can identify the possible added value of increased crossover between specialty coffee, scientific study, and other agricultural production practices. Where it does not explicitly show added value, it may at least raise questions that do.

Borrowing from Viniculture – Commercial Yeast Controlled Fermentation

Five years after the Final Technical Report surrounding the Ochratoxin study was released by the FAO, a scientific study conducted in India was released that experimented with the potential of using commercially available yeast (S. Cervisiae) to control fermentation and reduce mold growth that propagates OTA. The study found:

… a promising antagonistic and biocontrol potential of commercial yeasts in reducing the ochratoxigenic mold incidence and OTA contamination in coffee beans during on-farm processing. Use of yeast culture in coffee processing was found to be an affordable and cost effective approach in the management of A. ochraceus and OTA in parchment and cherry coffee production.3

The practice of using commercially available yeast (S. Cervisae) to control fermentation has been used in winemaking for a long time – where yeast culture is used to control the speed of fermentation relative to the sugar content of the must, and/or to neutralize and balance flavors. With coffee fermentation, this study found that commercial yeast applied in similar function during fermentation can control the growth of molds, thus helping control the presence of OTA. Furthermore, it found that it was a more economically viable option than other chemical means that achieve a similar result. Here we have scientific study, by way of long-standing viniculture practices applied elsewhere, offering a unique way to look at enhancing coffee quality at origin, all while offering a potentially more affordable and sustainable option for stakeholders at origin to do so. It’s this type of crossover that is at the very least intriguing, if not inspiring. What other practices might be out there waiting to be re-applied to coffee?

Coffee cupping prep at a lab in Kenya


If there is value for coffee in scientific study, do we have a common language to communicate this value? The study out of India also raises a conversation about calibration between the world of scientific study and specialty coffee. The study claims that “inoculation of yeast during processing was found to significantly reduce total mold incidence and OTA contamination… without affecting cup quality.”4 This ‘cup quality’ of course is according to the standards of those conducting the experiment – we can see here where ‘calibration’ becomes operative. The study explains

The cup quality was evaluated based on Hedonic scale with rating from 1 to 6 (6, good; 5, above average;4, average; 3, below average; 2, falling off; 1, poor). These ratings are a measure of cup quality such as acidity, body, and aroma or flavor. The rating presented in the current study is based on the coffee quality evaluation generally employed for marketing purposes in India and elsewhere.5

I’m guessing that few competent cuppers and/or Q Graders, feel that they can relate to this grading standard.6 This study was done in 2011, so it’s not simply outdated. It’s not the fault of those conducting the study that they didn’t meet Q standards, and the point is not to place blame. However, with this study as an example, we might ask what value gets lost in the translation of quality grading, if said translation happens at all? Is there value to be discovered through increased collusion between the grading standards of scientific study and those of specialty? The SCA’s collaboration with World Coffee Research has offered one affirmative in that regard. What is the possible role of calibration in activating the value and potential of work being done across fields of study, across various means of measuring quality, and in this case across continents? Has Specialty Coffee done enough work on its end to help build these connections? How would we go about doing so? I’d be remiss not to point out that the SCA’s Coffee Taster Pathway curriculum does touch upon other grading scales such as “Paired preference, ranking preference, and the hedonic scale” in order to “assist coffee professionals by increasing awareness of customer base preferences” 7. Should our strategy be to diversify our mastery of more grading standards so that we speak can speak various quality languages? Or is this variability itself inherently antithetical to the aims of wide-reaching calibration?

Moisture Activity

Moisture activity (aW) has somewhat recently come to be of equal or greater interest to roasters than moisture content. For a roaster, there’s the potential that understanding a coffee’s water activity might help better anticipate a coffee’s storage potential, or perhaps even add another variable to help determine that perfect roast. However, as the Study out of India suggests, there are ways in which this focus is a diversion from what moisture activity can be telling us about quality before it even leaves origin. Maybe moisture activity is better served when viewed as an indicator of mold growth potentials at origin. If there is a worthwhile benefit to moisture activity readings at farm level, what does a practical application of this look like? Is it reasonable to argue for the incorporation of moisture activity meters into the infrastructure of mills at origin? Even The FAO study is careful to point in their discussion that

“Use of well-established (and relatively expensive) models of moisture meters by some stakeholders is common. However problems with the maintenance, use and calibration of these instruments were widely noted.”8

Never mind the maintenance and calibration issues that have to be overcome and taught to those on the ground – what’s “relatively expensive” to you and I is likely an impossibility to the majority of smallholder farmers that, as buyers, we’ve come to cherish. This is just one of many inroads into an ongoing conversation that cannot be tackled here – that of how do we reasonably balance our demand for quality and an affordable price with sustainability efforts and the realities on the ground at origin? The FAO reports section on “Putting Moisture Content into Context” goes on to say “It should not be forgotten, therefore, that the ability of these stakeholders to accurately measure moisture content is also significant in relation to the income they receive.”9 Read one way this literally means that a farmer will get paid more or less by a buyer depending on the moisture weight of the coffee. Read another way it says, ‘the ability of these stakeholders to accurately measure moisture is related to the money they receive for their coffee, labor, etc.’ Insofar as accurately reading moisture at origin impacts quality, quality is dependent on the money the farmer receives for his or her coffee. Coffee doesn’t just cost more because it is quality – it also costs more because it costs more to make it a quality offering.

All this being said, with the study out of India that resulted from the original Ochratoxin study, it seems safe to say that there is potential value in a better working relationship between scientific study, various non-coffee agricultural practices, and the specialty coffee world. While there are doubtless many parties already tapping this potential, there might be a more public space and discussion for hitherto clandestine work among the specialty coffee community.


[2,8] Renata Clarke, John Frank, and Julius Jackson “Enhancement of Coffee Quality through prevention of Mould Formation – Final Technical Report”

[3] K. Velmourougane , Rajeev Bhat, T.N. Gopinandhan, et. Al “Management of Aspergillus ochraceus and Ochratoxin-A…” Biological Control, pg 215.

[4,9] Ibid.

[5] Ibid. pg 217.

[6] You can read more about the ‘9 Point Hedonic scale’ at

[7] GE308,