It Tastes Like An Intention

Alex Bermudez dreamed about water. Hot water first, then cold — poured over coffee in a sequence that had no precedent in any processing manual he'd read and no basis in any science he could cite. He woke up and told his brother Diego, who was skeptical. Then he went to his mother's kitchen, took her pans, heated water in one and filled the other with ice, and ran the first thermal shock trial in the history of coffee on what was, by every measure, a kitchen counter in Cauca, Colombia.

This was approximately 2017. There were no bioreactors. No UV sterilization chambers. No mass spectrometry readouts identifying hexanal and 2-heptenal in the aromatic output. There was a man, a dream, and cookware. Within seven years, the method he prototyped would produce coffees scoring above 91 points at Cup of Excellence, win the 2023 US Barista Championship, and sell at the Best of Panama auction for $10,000 per kilogram — roughly $4,500 per pound, for green coffee that had not yet been roasted. The total for one 55-pound lot: approximately $250,000.

There is, as of February 2026, no peer-reviewed scientific study confirming why it works.

The question of who invented it doesn't have a clean answer, either. Multiple accounts credit Wilton Benitez, the chemical engineer. Others name Diego Bermudez, the farmer. The Roeststaette Berlin account — written by Christopher Braemer, a trained journalist — credits Alex, the dreamer, the brother with the kitchen pans. The reality appears to be collaborative: Alex conceived it, Diego was skeptical but willing, Benitez brought the scientific infrastructure to formalize what intuition had initiated. They co-founded INDESTES SAS — Innovación y Desarrollo Tecnológico para la Caficultura — in 2017, which is either a company name or a mission statement, depending on your tolerance for acronyms. The partnership split eventually into distinct operations — Benitez's Granja Paraiso 92 and Diego's Finca El Paraiso — each pursuing variations on a method that belongs, in the strictest sense, to none of them individually and to all of them collectively.

The name is misleading. "Thermal shock" suggests a single intervention — a temperature change, something you could diagram on a napkin. The reality is a multi-day biotechnology operation that makes the thermal shock step look like an afterthought.

Wilton Benitez's protocol — Benitez being the chemical engineer with 26 years in coffee and 16 years of microbiology research, co-founder of INDESTES SAS, the company he and Diego Bermudez established in Villamaria, Caldas in 2017 — proceeds through stages that would be recognizable to anyone who has worked in pharmaceutical fermentation or artisanal brewing, and bewildering to anyone who has not. First: hand-picking only the ripest cherries, sorted by size and density. Second: double sterilization with ozonated water and ultraviolet light — a step unique to Benitez. Third: sealed bioreactors for 52 hours of anaerobic fermentation at 18°C, inoculated with selected yeast cultures from proprietary strain libraries. Fourth: depulping, with mucilage carefully recovered. Fifth: second anaerobic fermentation, 48 hours at 21°C, re-inoculated with locally isolated bacteria and yeast at precise ratios. Sixth: 68 hours of aerobic fermentation. Seventh — seventh, out of eight — the thermal shock itself: hot water at 40°C, then cold water at 12°C.

The thing the entire process is named for is its penultimate gesture.

Then controlled drying: 48 hours at 38°C in eco-dryers using cold CO2 and nitrogen, zero oxygen exposure. Total fermentation time across three rounds: 168 hours. Total equipment list: stainless steel bioreactors, hot water immersion systems, rapid cooling infrastructure, mechanical dehydrators, and monitoring rigs for pH, Brix, temperature, CO2, alcohol levels, and bacterial counts. Fantine, the processing education platform, delivers the accessibility verdict without sentiment: this requires "a high degree of knowledge and investment in infrastructure" and "specialized equipment and trained personnel" that are "not within the reach of every coffee producer."

Diego Bermudez's parallel protocol — documented by Barista Hustle with the technical reverence normally reserved for molecular gastronomy or haute parfumerie — pushes further into what he calls "deconstructed fermentation." Cherry juices are fermented separately from beans in stirred-tank bioreactors. Microbial cultures are grown in isolation to amplify cell counts. The cultured juice is recombined with depulped cherries for a final pressurized fermentation reaching 20 psi over up to 120 hours. His library of native cultures, built across six years of isolation and selection, includes strains engineered for specific aromatic outputs — the "Red Plum" yeast produces "large amounts of fruity esters, aldehydes and alcohols." Mass spectrometry has confirmed hexanal and 2-heptenal in the finished lots.

All of this from kitchen pans. Sort of.

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The proposed mechanism is elegant. It is also unverified.

The theory — advanced by producers, roasters, and educators, not by any peer-reviewed journal — holds that heating the parchment and silverskin layers of the coffee seed to 40–50°C expands cellular pores, allowing the aromatic esters and flavor precursors developed during the preceding 120-plus hours of fermentation to penetrate deeper into the bean structure. The subsequent cold shock — down to 4–12°C, or in extreme variations involving dry ice and liquid nitrogen, as low as -80°C — contracts those pores, "locking in the essences of the juice," in the phrasing of Trevor Clark at Black & White Coffee Roasters. Roeststaette Berlin proposes that the temperature fluctuations "create cracks in bean cell structure, releasing oils and aromas more easily." Fantine draws a parallel to pasteurization and vegetable blanching — rapid enzymatic halting. The Specialty Coffee Beans Australia site invokes the Maillard reaction, though this conflates roasting chemistry with processing chemistry in a way that should probably make chemists nervous.

These are not equivalent explanations. Pore expansion, cell wall fracture, enzyme inactivation, and microbial selection are distinct mechanisms with different chemical implications. That they are offered interchangeably — by knowledgeable industry sources who clearly understand coffee processing at a sophisticated level — is not a sign of confusion. It is a sign of the total absence of a validated framework. Nobody knows which explanation is correct. Possibly all contribute something. Possibly none captures the actual mechanism. Clark, to his credit, says this directly: "scientific research is needed to determine the true root of thermal shock's flavor impact." Nobody has funded that research.

August Kekulé dreamt the structure of the benzene ring in 1865 — a snake seizing its own tail, the hexagonal architecture that unlocked the entirety of organic chemistry. The dream was followed by decades of verification. Alex Bermudez's dream of hot and cold water has been followed by seven years of commercial dominance and zero controlled studies. Nassim Taleb has a framework for this — practitioners outrunning theorists, craft arriving before the science that explains it, which is basically how all of human technology worked before the Enlightenment reversed the sequence. Whether that framing is reassuring or alarming depends on how much you trust a $4,500-per-pound cup of coffee to be its own evidence.

What is not disputed, by anyone, is that the coffee tastes different. Pronounced sweetness, intense fruit-forward aromatics, reduced astringency. Tasting notes across dozens of independent evaluations: cotton candy, rum pralines, wild strawberries, fruit jelly, lychee, peach, red plum. These are not conventional coffee descriptors. They belong to the vocabulary of confection, of cocktail menus, of something designed rather than grown. And this — the sense that the flavor is too intentional, too constructed, too much like a product of engineering rather than agriculture — is precisely what makes people uncomfortable. There is an implicit assumption in specialty coffee that great flavor should feel discovered, not manufactured. That it should emerge from the convergence of soil and altitude and season — the terroir narrative — rather than from bioreactors and proprietary yeast strains. Thermal shock violates this assumption with a cheerfulness that its critics find difficult to forgive. The coffee doesn't taste like a place. It tastes like an intention. And intentions, in an industry that has built its entire premium structure on the mythology of origin, are destabilizing.

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Whatever the mechanism, competition judges have consistently scored thermal shock coffees as if they know something the researchers don't.

Isaiah Sheese of Archetype Coffee in Omaha won the 2023 US Barista Championship using a Pink Bourbon grown by Lucy Fernanda Galindez at Finca Buena Vista in Huila, processed by Diego Bermudez at Finca El Paraiso. His scores — 661.5 in semifinals, 672 in finals — were the highest of the weekend by wide margins. He placed fourth at the subsequent World Barista Championship using the same coffee. The decision to compete with it was revealing in its rationale: Bermudez's processing, Sheese told interviewers, is "so controlled that he can repeat the process every time." In a competition culture built on the romantic assumption that exceptional coffee is rare — a product of perfect convergences between terroir and season and craft — the ability to manufacture repeatability is either a feature or an existential challenge, depending on where your economic interests lie.

By 2024, the broader category had consumed the circuit's center of gravity. Eighty percent of coffees used at the US Barista Championships involved some form of anaerobic fermentation — a figure that would have been inconceivable a decade earlier, when washed Ethiopians and honey-processed Costa Ricans dominated routines. The Cup of Excellence added an Experimentals category in October 2023, its first rule change in 24 years, precipitated by requests from the Brazil Specialty Coffee Association. The inaugural winner: a 91.32-point anaerobic fermented Geisha from Fazenda Rio Verde. The institution that had resisted for a quarter century adapted in a single season.

Benitez's Granja Paraiso 92 has accumulated 64 competition awards. At the April 2019 SCA event in Boston, his coffee sold for $54 per pound — a Colombian record at its first international auction — purchased by Procafecol Juan Valdez, the institutional embodiment of Colombian coffee identity acquiring, at a premium, innovation from one of its own producers. Diego's 2018 Cup of Excellence double anaerobic Bourbon placed in the top ten but sold for the highest price at auction: $54.10 per pound, breaking the previous Colombian record of $50.50.

The competition circuit has served, as competition circuits reliably do, as both legitimation engine and amplification device. The scores made thermal shock legible to an industry that treats cupping scores as its closest approximation of objective truth — even when nobody can explain the chemistry that produced them.

The consumer market has followed, predictably, at a delay and a premium. In the San Francisco Bay Area, the SF Chronicle reported in 2025 that shops brewing co-fermented coffees had "doubled, if not tripled" over the prior year. Ain't Normal Cafe in Oakland charges $20 per cup. Black & White Coffee Roasters carries multiple Benitez thermal shock varieties — Caturra, Gesha, Red Bourbon, even a decaf — alongside Diego Bermudez's lots. Roasters in Australia, Europe, and across North America now feature thermal shock lots as limited releases, positioned in the same retail register as natural wine and single-origin chocolate: scarcity plus story plus a price point that functions as its own credential. Ming Wood, co-owner of Moonwake Coffee, described co-ferments as "really fun" — the kind of casual endorsement that signals a category has crossed from connoisseur curiosity into something approaching cultural legibility.

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The Best of Panama is the highest-value coffee auction in the world. In 2024, it became ground zero for what amounted to a declaration of economic warfare conducted in the language of aesthetic purity.

The Specialty Coffee Association of Panama disqualified four coffees, declaring them "altered from their natural DNA expression, likely with the intent to score higher and win by using foreign additives." SCAP President J. Hunter Tedman signed the statement, calling on global competition bodies to prevent "the artificial homogenization of different terroirs and varietals worldwide." The language condemned "co-fermented" and "thermal shock" by name, calling both terms "deceptive" and deployed "to mislead buyers."

One disqualified lot belonged to the Hachi Coffee Project — a venture co-founded by Diego Bermudez with Allan Hartmann of Rocky Mountain Coffee in Panama and Matheus Antonaci of INC Specialty. Hachi's work extends beyond thermal shock into explicit biotechnology: enzyme treatments with pectinase and glucosidase, biocatalysis for aromatic manipulation, plant tissue culturing for genetic preservation. Their response was calibrated to a specific temperature of institutional restraint: "Truth always prevails. The best way to face a situation like this isn't through argument, but by giving people real proof of what we're doing."

The conflict-of-interest dimension drew less restrained analysis. Tedman owns Black Moon Farm. His Chiroso variety won first place in the Best of Panama Varietals category the same year he signed the disqualification statement. Wilford Lamastus of Lamastus Family Estates won Natural Gesha, and his social media accounts distributed Tedman's anti-co-ferment text. Chris Kornman at Royal Coffee — writing with the careful precision of someone who has calculated exactly how much institutional goodwill he is spending — dismantled SCAP's language point by point. "Altered from its natural DNA expression" was scientifically illiterate: processing does not alter DNA. "Natural" was itself a misapplied term. And "artificial homogenization of different terroirs" contradicted Panama's own importation of Ethiopian Geisha cultivars in 2004 — a move that, by SCAP's own definitional framework, artificially introduced a non-native varietal to Panamanian soil.

The numbers beneath the rhetoric: the 2024 Best of Panama top lot sold for $10,000 per kilogram. The previous year's auction averaged $868 per pound. When competition winners author the rules that disqualify their competitors, "authenticity" begins to function less as an aesthetic principle and more as what it plainly is — a market protection mechanism with philosophical window dressing.

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The word *terroir*, borrowed from wine with all of wine's ideological freight intact, carries a specific payload in specialty coffee: that the best beans are expressions of place, and that place — altitude, soil, microclimate, genetic heritage — should be the primary determinant of value. This framework benefits producers whose geography is already prestigious. In structural terms, it is a theory of value that rewards inherited advantage.

The Forgotten Forest published an editorial tracing the concept to its origins in the French wine industry, where it was deployed specifically to help wealthy estates undercut smaller producers. Applied to coffee, the same logic allows "buyers with quite a lot less risk and precarity" to "condemn rural, economically disadvantaged farmers for not being 'up to standards.'" Kenneth Davids, editor-in-chief of Coffee Review, offered the aesthetic counterposition with genuine conviction: "Are we considering the excellence of coffee production from tree to bean as a coherent act of tradition and passion, or are we simply celebrating cute tricks at the end of that process?" It was, he reported, the most frequently asked question during his November 2024 book tour in Taiwan — which tells you something about the geography of this anxiety.

Both positions contain real insight and real evasion. Davids's "cute tricks" framing dismisses the 168 hours of controlled fermentation, the six-year microbial library, the bioreactors and the mass spectrometry — these are not tricks, cute or otherwise. The Forgotten Forest's colonial critique, while structurally sound, risks collapsing a genuine aesthetic tension into pure power analysis. Colombian producer Elkin Guzman cut through both registers: "If people hadn't asked for bolder flavors, we wouldn't have produced them." James Hoffmann sided with the simplicity of economics: "If a producer can make more money, then broadly I'm behind it."

Fresh Cup surfaced what nobody wanted attributed: "By talking about processing, it obscures the issue that we haven't been paying fair prices since the beginning." Anonymous, of course. An SCA 2024 study confirmed it empirically: across decades of stated commitment to farmer equity, "farmers receive less payment while exporters and roasters receive more." Thermal shock did not build that gap. But thermal shock — by producing a $10,000-per-kilogram lot whose value was generated primarily through processing rather than geography — made the question of who captures the value of innovation functionally unavoidable.

Hachi's mission statement adds the temporal dimension that nobody in the terroir camp seems eager to address: by 2050, climate change may eliminate 50% of suitable coffee-growing regions. If that projection holds, processing innovation migrates from luxury differentiation to agricultural survival strategy. The controlled fermentation environments, the microbial libraries, the precision monitoring systems — all the infrastructure that Panama's establishment would prefer to classify as "deceptive" — become essential tools for producing viable specialty coffee from increasingly marginal land. The current debate about legitimacy may, in retrospect, look like an argument about furniture arrangement on a ship that everyone can see is listing.

Second State Coffee observed what might be the debate's most structurally damning fact: "there are no governing bodies administering standardization over styles of processing." The term "thermal shock" has no legal definition, no industry consensus, no regulatory framework. The Best of Panama's own submission guidelines used the phrase "no propio" — not characteristic, not typical — rather than naming specific prohibited techniques, creating what Kornman called a fundamental ambiguity around what is actually banned. An industry fighting over the legitimacy of a process that it cannot define, governed by rules that it cannot articulate, evaluated by science that does not exist.

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CoffeeSource, a Czech specialty importer, predicts thermal shock will "probably never become more widespread" — constrained by cherry sugar content, altitude, climate, and the capital requirements that separate a kitchen counter from a bioreactor facility. Vibrant Coffee Roasters warns that heavily processed coffees "de-gas and start to stale much, much faster" than traditional lots, that their peak flavors vanish within weeks rather than months. The product is fragile, expensive, and stubbornly unscalable. The 168-hour protocol does not compress.

Coffee Review's 2025 Top 50 included 17 coffees processed through fermentation-led techniques. An Oakland cafe charges $20 per cup. The category grows the way luxury niches grow — not by becoming accessible but by becoming aspirational, which in consumer markets amounts to the same thing provided you're standing at the correct end of the value chain.

Nobody has proven that the pores expand. Nobody has proven that they contract. Nobody has funded the controlled study that would settle the question — which is itself, arguably, the most revealing data point in the entire story. An industry willing to spend $4,500 per pound on the result but unwilling to commission the research that would explain it. The dream came first. The kitchen pans came second. The science, whenever it arrives, will arrive last, and will almost certainly be less interesting than what it seeks to verify.

Alex Bermudez had the dream. The industry built the price. The pores remain, for now, a theory.