What Beaujolais winemakers and craft coffee roasters really have in common

Carbonic Maceration: the unlikely bridge between wine and coffee

The deeper you go into the worlds of natural wine and specialty coffee, the more you realise: the methods that define them aren’t just trendy — they’re biochemical revolutions. One such method, born in the cellars of Beaujolais and now embraced by avant-garde coffee producers, is carbonic maceration.

This technique, long associated with juicy, aromatic red wines, has crossed the aisle. It’s now being used — with stunning results — to ferment coffee cherries, unlocking vivid fruit profiles and unexpected complexity. But how does it work in each case?

In Beaujolais: whole grapes, whole flavor

In the heart of Beaujolais, winemakers have been practicing carbonic maceration — or more precisely, semi-carbonic maceration — since the 1930s. It begins not with crushed fruit, but with whole clusters of Gamay, carefully hand-picked and stacked into sealed vats.

Here’s what happens:

• The grapes at the bottom are gently crushed under the weight of those above, releasing juice.
• This juice starts to ferment spontaneously, releasing CO₂, which fills the tank.
• The intact grapes at the top are now sitting in a low-oxygen, CO₂-rich atmosphere, triggering intracellular fermentation — a process where enzymes inside the grape begin to transform sugars and acids, even before the skins break.

This technique is what gives Beaujolais Nouveau its iconic banana and red fruit aromas, but it’s also used more subtly in the region’s serious crus — like Fleurie or Chiroubles — to produce expressive, lifted wines with delicate tannins and a vibrant, youthful energy.

In Coffee: from the vineyard to the fermentation tank

Now imagine applying that same principle — fermenting the whole fruit in a CO₂-saturated environment — not to grapes, but to coffee cherries.

That’s exactly what pioneering specialty coffee roasters and their producer partners have been doing. Whole, perfectly ripe coffee cherries are placed in sealed tanks — either with added CO₂ or with oxygen displaced naturally by fermentation. Inside, enzymes and native microbes get to work, metabolising sugars and breaking down mucilage from the inside out.

The result?

• Wild, fruit-forward profiles — strawberries, tropical fruits, bubblegum, florals.
• An unusually clean, structured acidity, reminiscent of natural wine.
• A tactile sensation in the mouth that cuppers describe as almost “vinous”.

In essence, carbonic maceration has become a crossover technique, proof that fermentation is not just a step in production — it’s the heart of flavor creation.

The biochemistry behind fruit-forward profiles

What makes a wine taste like ripe cherry and banana? What gives a coffee the aroma of red berries and violet florals?
Spoiler: it’s not flavouring agents. It’s chemistry — specifically, what happens during fermentation. And whether you’re macerating Gamay grapes in Régnié or fermenting Sidamo cherries in a tank in Yirgacheffe, the biochemical ballet is strikingly similar.

Inside the fruit: shared enzymatic pathways

Once sealed off from oxygen, both grapes and coffee cherries switch from aerobic respiration to anaerobic metabolism — a move that flips a crucial switch in flavour development.

In both cases, enzymes begin to break down malic acid, simple sugars, and cell wall components. This process, known as intracellular fermentation, doesn’t require yeast at first — it starts with the fruit’s own internal chemistry.

In wine:

• Malic acid is partially degraded, softening the wine’s acidity.
• Sugars are partially converted into alcohol and metabolic precursors.
• This leads to the formation of cinnamate esters, benzaldehyde, and other aromatic molecules.

In coffee:

• The same sugar and acid transformations occur inside the cherry.
• Native microbes begin to produce precursor compounds that will evolve during roasting.
• The result is enhanced complexity and sweetness without over-fermentation.

These shared pathways show that what’s inside the fruit matters just as much as what’s done around it.

Esters, terpenes and volatile phenols

Here’s where it gets delicious. The signature aromas that define both Beaujolais and carbonic macerated coffee come from the same families of volatile compounds.

In wine:

• Isoamyl acetate → Banana
• Ethyl cinnamate → Spicy red fruit
• Phenylethanol → Rose
• Terpenes → Floral lift

In coffee:

• Ethyl acetate, linalool, and geraniol all contribute to the perception of brightness, florality, and fruitiness.
• These are either produced during fermentation or revealed during roasting.

Interestingly, some coffees even show vinous textures — not just in aroma, but in the tactile feel on the palate. This has led cuppers to describe such brews as “pinot-esque” or “Gamay-like.”

Science backs it up: sensory studies confirm higher concentrations of esters, terpenes, and higher alcohols in carbonic coffees — just as they do in Beaujolais wines. The overlap isn’t just poetic — it’s molecular.

Precision, patience, and the art of control

Great wine and great coffee don’t happen by accident. They demand patience, obsessive control, and a deep respect for raw material. Whether in a stone cellar in Vaux-en-Beaujolais or a roastery in Geneva, quality lives in the fine print — in the temperature, the timing, the volume, and the restraint.

Small batch, big attention

In the Beaujolais, most winemakers work on a parcel-by-parcel basis. That means fermenting grapes from each vineyard plot separately, adjusting techniques to suit the soil, aspect, and ripeness. There’s no “one-size-fits-all” recipe — just observation and adaptation.

The same holds true for specialty coffee roasters like Chronic., who operate on a small-batch model. They roast each lot independently, calibrating temperature, airflow, and roast curve with surgical precision. One origin might be delicate and floral, requiring a light touch. Another might need more development to unlock tropical depth.

Why it matters:

• Small batches allow micro-adjustments: more control, less margin for error.
• Each lot expresses its origin more clearly — terroir in the cup or the glass.
• The producer can respond to variables — climate, moisture, sugar levels — in real time.

Craft, in both cases, is not about scale. It’s about intention.

Why temperature and timing change everything

Both Beaujolais winemakers and coffee processors treat temperature like a sacred variable. Get it wrong, and you risk ruining a year’s work. Get it right, and magic happens.

In carbonic maceration for wine:

• Optimal temps hover between 18–30°C.
• Too hot, and volatile aromas are lost or fermentation runs wild.
• Too cold, and enzymatic activity slows, leading to underdeveloped wines.

In carbonic fermentation for coffee:

• Cherries are often kept at 18–30°C, depending on the desired profile.
• Lower temps preserve acidity and nuance.

While lower temperatures tend to preserve acidity and nuance, going too low can slow enzymatic activity to the point of muting complexity. On the flip side, excessively high temperatures can push fermentation into overdrive, flattening aromatics and producing a coarse, rustic profile. The sweet spot is narrow — and actively managed.

These temperatures are actively monitored with probes, insulation, and controlled tanks. The timing is equally crucial: in Beaujolais, maceration can last 4 to 7 days; in coffee, anywhere from 24 to 120 hours.

The guiding principle? No overdoing. No shortcuts. No improvisation.

Microbial terroir: the invisible hand behind flavor

Behind every glass of wine and every cup of coffee is a cast of microscopic characters — yeasts, bacteria, fungi — quietly shaping the aromas we perceive. These microbes don’t just ferment sugars; they whisper the story of a place. Welcome to the world of microbial terroir.

Yeasts on the grape, microbes in the cherry

In Beaujolais, many winemakers forgo commercial yeasts, opting instead for indigenous fermentations. These are fueled by the yeasts naturally present on the grape skins, the winery walls, the air — even on the pickers’ hands. The microbial ecosystem is specific to the vineyard and cellar, evolving over years into a kind of microbial fingerprint.

Scientific studies show that distinct yeast populations exist from one wine region to another, and even from one vineyard to the next. These organisms aren’t neutral — they actively shape the wine’s aromatic profile, often producing more esters, more phenols, and more nuance than lab-grown strains.

Coffee producers are taking note.

In carbonic coffee fermentations, many are now embracing wild fermentations — allowing local microbial populations to do the work, just as in natural wine. The skins of the coffee cherry, the soil, the air in the processing shed — all contribute to a unique microbial mix that can’t be replicated industrially.

The result? Coffees that taste not just fruity or clean, but deeply of their origin.

Spontaneous fermentation and the taste of place

What does it mean when we say a product “tastes of place”? It means that the environment has left an imprint not just through climate and soil, but through its biology — its living culture, quite literally.

In both wine and coffee:

• Spontaneous fermentations preserve microbial biodiversity.
• Indigenous flora produce a broader spectrum of volatile compounds.
• The final product has greater aromatic complexity and a less standardized profile.

This kind of fermentation requires trust — in nature, in time, in the fruit itself. It also requires cleanliness, attention, and a bit of nerve: spontaneous means uncontrolled, but not unmanaged.

Microbial terroir is still an emerging field in coffee science, but it’s already clear: yeasts are part of the origin story. And just like in Beaujolais, the best producers are learning to listen to them.

Timing is everything: harvest, maturity and the race against decay

In both wine and coffee, flavour is time-sensitive. From the moment a grape is picked or a cherry is plucked, a biological clock starts ticking. The difference between brilliance and mediocrity? Often, just a few hours — and an uncompromising eye for ripeness.

Perfect fruit or nothing

In the Beaujolais, grapes are hand-harvested at peak maturity, often in small crates of 13 kg to prevent crushing. Pickers select only healthy, intact bunches — underripe berries mean sharpness, overripe ones risk rot. The sweet spot is narrow, and once the bunch leaves the vine, oxidation begins.

On the coffee side, selective picking is standard for high-end lots. Trained harvesters choose only the ripest cherries — those deep red or purple in colour, heavy with sugar, firm to the touch. Immature cherries produce vegetal or sour notes; overripe ones introduce fermenty defects. As in wine, there’s no room for compromise.

Both crafts treat harvest not as logistics, but as surgical precision — a make-or-break moment in the pursuit of flavour.

The 24-hour rule

Once picked, the fruit must be processed fast — and with care.

In Beaujolais:

• Grapes are often moved within hours to the fermentation tanks.
• The goal is to keep them intact and cool, to preserve the skin flora and avoid unwanted oxidation or pre-fermentation.
• Time is managed down to the hour — especially in warm vintages, where microbial activity can spike early.

In coffee:

• Speed to fermentation is just as critical.
• Cherries that sit too long post-harvest — especially in tropical climates — start to ferment spontaneously, often in uncontrolled, undesired ways.
• Best practices for washed coffees limit this delay to under 24 hours — enough time to depulp before wild microbes take over. For carbonic maceration, however, whole cherries often enter sealed tanks almost immediately after harvest, and the anaerobic phase can last anywhere from 24 to 120 hours or more, depending on the desired outcome.

What happens during that short window is decisive. The fruit is alive. The enzymes are active. The line between fermentation and spoilage is razor-thin. But in the right hands, with the right timing, that window becomes a doorway — into aroma, complexity, and authenticity.

The ritual of tasting: when cuppers and sommeliers speak thesame language

Wine and coffee are not just agricultural products. They’re sensory experiences, decoded sip by sip. And while their settings may differ — one under chandeliers, the other in minimalist cafés — the structure of their tasting rituals is strikingly similar. Precision meets intuition. Technique meets emotion. It’s a choreography of the senses.

A shared methodology of the senses

In the wine world, tasting follows a well-established protocol:

• Visual: clarity, colour, viscosity.
• Nose: intensity, complexity, typicity.
• Palate: balance, length, texture, acidity, tannin structure.
• All scored according to objective standards, under controlled conditions: neutral lighting, no perfumes, silence.

Coffee tasting — or cupping — isn’t just a hipster ritual. It’s a global standard among professionals:

• Dry aroma of the ground beans.
• Wet aroma after infusion.
• Then, after a timed steep (typically 4 minutes), the crust is broken with a spoon to release volatile compounds.
• Tasters slurp coffee forcefully to aerate it, covering the palate evenly.

Attributes are evaluated using a cupping form with scoring for aroma, acidity, body, balance, sweetness, aftertaste, and more.

Both disciplines rely on calibrated vocabularies. Both are designed to minimise bias. And in both, the goal is the same: to interpret and communicate flavour with as much honesty and precision as possible.

From slurps to swirls: decoding aroma and balance

Despite the very different vessels — ISO wine glass vs. cupping bowl — the language of description overlaps more than you might expect:

Wine Descriptor	Coffee Equivalent
Cherry, Raspberry	Red berries
Floral (violet, rose)	Jasmine, bergamot
Fresh acidity	Brightness
Silky mouthfeel	Clean body
Long finish	Lingering aftertaste

Both sommeliers and cuppers are trained to detect volatile aromatic compounds (like esters and aldehydes), to assess acidity not as sharpness but as structure, and to appreciate balance over brute intensity.

What’s even more telling: the best Beaujolais wines and the best carbonic coffees are often described with the same adjectives — playful, fruit-forward, elegant, juicy, clean, floral. The line between them is sometimes so thin, the distinction is one of temperature, not essence.

Sustainability and Craft: When Small is Powerful

It’s not just taste that links winemakers and coffee roasters — it’s philosophy. Both are increasingly defined not by mass production, but by a commitment to craft, community, and sustainability. From the steep vineyards of the Beaujolais hills to the micro-roasteries of urban Europe, a new generation of artisans is emerging. And they’re doing things differently.

Shared values: people, planet, and purpose

Producers like Chronic in Geneva are part of a growing movement in specialty coffee:

• Direct trade relationships with smallholder farms
• Organic and Fair-Trade sourcing
• Zero capsule policy
• Slow roasting in small batches to respect the integrity of the bean
• Transparent communication around origin, process and impact

Beaujolais winemakers, especially in the natural wine scene, mirror this ethos:

• Many farm organically or biodynamically, even if uncertified.
• Vinifications are low-intervention, allowing the land to speak.
• Estates are often family-run, passed down through generations.
• There’s a growing emphasis on local economies, biodiversity, and carbon-conscious practices.

In both cases, craft means accountability — to the environment, to the grower, and to the drinker. Small is not a limitation. It’s a choice.

The new artisans

Neither wine nor coffee is stuck in the past. What defines the best artisans today is their ability to honour tradition while rewriting its rules.

In the Beaujolais, this means:

• Returning to whole-cluster fermentation and native yeasts
• Treating each vineyard like a separate narrative
• Pushing back against over-extraction and standardisation

In specialty coffee:

• Roasters and producers experiment with fermentation variables — temperature, oxygen levels, duration — much like winemakers.
• Roast profiles are adjusted not for volume, but for nuance.
• Education, transparency and sensory literacy are central to the craft.

Both groups are data-driven but intuitive, scientific yet artisanal. They take risks. They fail. They learn. And above all, they share one ambition: to make something that matters — to themselves, to the grower, and to the person holding the glass or the cup.