The Wine That Smells of Vinegar

Volatile Acidity, Sulphites, and pH: A Producer's Technical Perspective on Natural Wines from Samos

The Moment of the "Funky" Wine

My first encounter with what is now called "funky wine" was not rooted in theory or oenological analysis. It was a lived experience, deeply social and cultural. Picture Paris in the mid-2010s. The financial crisis had reshaped many lives. A younger generation began to abandon traditional career paths, turning instead to the land and winemaking. This was not merely a continuation of family traditions or a result of formal training; it was a conscious choice to start anew.

What emerged was not just a continuation of earlier natural wine movements. It was something distinct. A new group of producers, often lacking deep technical experience, sought expression, experimentation, and personal narrative.

The first wines I tasted from this scene often displayed visible technical deviations. Oxidation, elevated volatile acidity, and aromatic instability were common. Yet, the experience extended beyond the glass. The presentation was equally defining. There was intense enthusiasm and emotional pride, as if each bottle represented a personal act of creation.

The labels reinforced this sense of identity. Handmade and simple, often designed by the producers or their friends, they became extensions of the winemaking act. The wine and its image were inseparable, forming a single narrative.

Over time, this approach evolved into a recognizable movement. An entire ecosystem emerged around these wines, with specialist wine bars and sommeliers catering to consumers seeking not just a tasting experience but a cultural identity. Thus, the term "funky" began to describe less a technical reality and more an aesthetic category — at least, that’s how I perceived it.

The Confusion That Followed

As this aesthetic gained traction, a reductive interpretation emerged: wines with higher volatile acidity were deemed more "natural," while those with lower levels were seen as more interventionist or technically controlled.

This interpretation is understandable but analytically flawed. Volatile acidity is not an indicator of philosophy or identity. It results from specific microbiological processes during fermentation, ageing, or storage.

A wine can originate from organic farming, be fermented with indigenous yeasts, and bottled with minimal intervention, yet still exhibit low volatile acidity. Conversely, a conventionally made wine may show elevated VA levels under certain conditions. VA is not an indicator of intention; it reflects systemic conditions. The real issue lies in conflating two distinct languages: biology, which describes what occurs, and aesthetics, which conveys what it means.

What Volatile Acidity Actually Is

Volatile acidity primarily refers to volatile organic acids, with acetic acid being the most significant. This is the same compound that gives vinegar its distinctive smell. In wine, it often coexists with ethyl acetate, which can contribute aromatic expressions ranging from fruity and ethereal to more pronounced solvent notes. The concentration and surrounding chemical environment dictate these nuances.

Small quantities of volatile acidity are present in nearly all wines. In certain contexts, they can enhance aromatic complexity and impart a sense of vitality. The key is not its presence but how it integrates into the wine's structure.

Its production is mainly associated with acetic acid bacteria, particularly Acetobacter, which convert ethanol into acetic acid in the presence of oxygen. Other microorganisms, like Brettanomyces, known for its characteristic barnyard aromas, also produce acetic acid as a by-product. Certain lactic acid bacteria can influence volatile acidity through specific metabolic pathways. This multiplicity of sources means that VA is never the result of a single factor.

Oxygen is a decisive variable. A wine's exposure to it, combined with pH, alcohol potential, hygiene conditions, and technical management during winemaking and ageing, directly influences how VA develops.

In some winemaking approaches, particularly small-scale production, volatile acidity is not merely something to avoid. Instead, it can be integrated into the overall sensory profile. This was the approach I applied with the Sous le Végétal wines, where VA was treated as part of a unified structural whole, evaluated primarily through the wine's behaviour over time and in the bottle.

It's worth noting that the sensory threshold for detecting volatile acidity is often lower than the legal limits in most countries. A wine may fall within international technical limits while still having perceptible VA in its final profile.

From Microbiology to Market Standards — How VA Became a "Fault"

The classification of volatile acidity as a sensory fault did not arise from a single decision or a unified definition. It developed gradually, shaped by microbiological science, industrial wine development, and the need for commercial stability in an increasingly globalized trade. To grasp the current debate, a brief historical excursion is necessary.

Louis Pasteur played a pivotal role in this process during the nineteenth century. His studies on fermentation revealed that wine is not a static chemical liquid but a biological system influenced by microorganisms. He established a connection between bacterial presence and acetic acid production, providing the first scientific framework for understanding acetic deterioration.

As wine production and distribution expanded internationally, particularly in the nineteenth and early twentieth centuries, stability became crucial. Wines were transported over long distances and often under challenging conditions. In this context, elevated volatile acidity became associated with spoilage during transit or storage.

Advances in analytical chemistry allowed for quantifying quality. VA gradually became one of the principal indicators of microbiological stability and oxidative risk. When organizations like the International Organisation of Vine and Wine (OIV) began harmonizing technical standards in the twentieth century, the permissible limits were not philosophical definitions of wine but codifications of existing practical consensus between science, sensory evaluation, and market requirements. Over time, these standards significantly shaped perceptions of what wine should taste like.

Enter Sulphites — and Why the Relationship Is Causal

Any serious discussion of volatile acidity inevitably leads to sulphites. The connection between them is not merely correlative; it is causal and deserves precise explanation.

Sulphur dioxide (SO₂) acts in wine on two levels: as an antioxidant and as an antimicrobial agent. Its effectiveness at the second level depends critically on pH. At low pH values, a greater proportion of total SO₂ remains in free, molecular form — the biologically active form that inhibits bacteria and undesirable yeasts. At higher pH, the same quantity of SO₂ becomes bound in inactive forms, offering substantially less protection. In essence, two wines with identical total sulphite levels may have entirely different degrees of microbial protection based on their respective pH.

This mechanism connects sulphites directly to VA. Acetobacter and Brettanomyces — the main producers of acetic acid in wine — are precisely the populations that free SO₂ inhibits. A producer opting for zero sulphites assumes heightened microbial risk, which must be compensated through other means: low pH, rigorous hygiene, limited oxygen exposure, and healthy raw materials. This is neither good nor bad; it is simply true.

Sulphites are widely used in food technology as antioxidant and antimicrobial agents — in dried fruits, fruit juices, jams, and preserved foods. Their use in wine predates modern industrial oenology by centuries.

In specific terroirs like Samos, the combined influence of vineyard site, microclimate, and careful fruit selection can create conditions that support production with minimal or zero added sulphites. This is not based on ideology but on a system of parameters — low pH, raw material integrity, rigorous selection — that reduce microbiological and oxidative risk without chemical intervention.

The critical point is not the opposition between "sulphites or no sulphites," but understanding how each producer manages the balance between microbial control, oxidation, and sensory identity.

The International Debate Today

Volatile acidity occupies a space between science and aesthetics, and regulations reflect this tension. The European Union sets maximum limits of 1.08 g/l for white wines and 1.20 g/l for reds, while the United States (TTB) applies a single limit of 1.40 g/l. The OIV proposes similar frameworks, with variations by category and wine type. These limits reflect commercial and microbiological logic, not aesthetic preference.

The debate within the natural wine world has grown more nuanced over the past decade. Alice Feiring, a leading advocate for wines made without additives, argues that VA — when resulting from living fermentation rather than inadequate control — constitutes an expression of terroir rather than a fault. Conversely, Jamie Goode, who combines scientific training with wine criticism, contends that tolerance of high VA often confuses conscious aesthetic choice with technical failure, serving neither producers nor consumers.

An increasing number of professionals — sommeliers, importers, critics — now explicitly distinguish between high VA as a deliberate aesthetic choice and high VA as the result of insufficient control. The difference lies not only in intensity but in the role it plays within the wine's final profile — and, crucially, in whether the producer can explain it technically.

Design or Default

Returning to the aesthetic dimension that sparked this discussion, it becomes clear that much of what is described as "style" or "movement" in wine is merely different interpretations of the same reality. Volatile acidity, sulphites, and choices surrounding intervention or non-intervention acquire meaning not only as technical parameters but as elements of a broader aesthetic language shaped by history and culture.

The so-called "funky" aesthetic, like any other aesthetic in wine, is neither a universal standard nor a unified system of values. It is a specific expression that, in certain moments and places, became particularly visible and influential. This does not make it an interpretive framework for natural wine as a whole, nor can it serve as the sole measure of understanding such a complex field.

Ultimately, wine remains an object where technical reality and aesthetic perception coexist without ever fully coinciding. Perhaps the most useful insight is not to choose between these perspectives but to recognize when one attempts to explain something that belongs to the other.

When aesthetics become dogma, they cease to explain wine and begin to oversimplify it. The real issue is not the existence of different aesthetics in wine but the moment they are mistaken for absolute truths.

In this vibrant landscape of natural wines, understanding the nuances of volatile acidity, sulphites, and pH can deepen our appreciation for the artistry behind each bottle. Embracing these complexities allows us to celebrate the authentic, terroir-driven wines that reflect the unique character of Samos.