Whenever I occasionally post about “natural wine” on X (formerly Twitter), those posts tend to be shared relatively widely for my account size. This simply indicates how many people react to this particular keyword.
In recent years, especially in Japan, the term “natural wine” has clearly become more visible. At the same time, I suspect many people still do not really know what it is supposed to mean in concrete terms.
Because it is also referred to as “shizen-ha wine” (literally “natural-style wine”), quite a few people appear to vaguely understand it as “a healthy, body-friendly wine, like organic (bio) wine.”
However, while “bio wine” (Bio wine) and “natural wine” can refer to the very same liquid inside the bottle, the underlying concepts differ substantially. In some cases, one could treat “natural wine” as a subset of “bio wine” (natural wine ⊂ bio wine), but it is certainly not true that “every bio wine is automatically a natural wine.”
This article examines the relationship between these two categories—which appear similar but are in fact different—and the “natural-style wine” that is often conflated with them in practice, from the perspective of wine production (enology).
By the end of this article, you should at least be able to resolve the fundamental confusion between bio wines, natural wines, and what is currently referred to as “natural-style wines.”
What Does “Bio” Mean, and What Does “Natural” Mean?
Before discussing the practical differences in winemaking, it is useful to clarify what each term is supposed to denote. If you are not familiar with either “bio” or “natural,” you may start by focusing on this section alone.
“Biologique”: Familiar and Yet Not Quite
Throughout this article, “Bio” refers to “biologique,” which, put very simply, corresponds to organic viticulture.
That said, what falls under “Bio” does not fully match the common Japanese image of “organic cultivation.” The reference point is the EU’s harmonized organic certification scheme, and the key question is whether the producer complies with the rules defined within that framework. Consequently, the practical content of “Bio” may differ from what the term “organic” typically evokes in Japan.
Strictly speaking, “biologique” (Bio) and “biodynamic” viticulture are separate categories. For the sake of clarity and focus in this article, however, I will not draw a strict line between the two and will treat them together where it does not affect the argument.
Likewise, I will treat “Bio” (biologique) and “Eco” (écologique) as effectively synonymous in this context. When “Bio” and “Eco” appear side by side in the text, they should be read merely as alternative labels for the same basic concept.
From this point onward, I will use Bio to denote viticulture and winemaking conducted in accordance with the rules defined in the EU organic certification framework, and Eco as a synonymous term where needed.
The core of Bio is to minimize environmental impact in grape growing and wine production. In other words, the central concept is to avoid methods that impose a heavy burden on the global and local environment, and to adopt alternative practices that reduce that burden.
For this reason, the main focus of Bio regulations lies not in the cellar, but in the vineyard.
There are, of course, several rules that directly affect winemaking. In broad terms, they include upper limits on the use of sulfur dioxide (sulfur dioxide, SO₂; sulfites), restrictions on certain winemaking techniques, and requirements to use Bio-compliant inputs such as sugar for chaptalization and dry yeast.
In practical terms, however, Bio’s primary focus with respect to SO₂ is not cellar additions but its use in the vineyard as a plant protection agent. Many of the restricted cellar technologies are not those that an ordinary winery would use on a daily basis. Likewise, the requirement to use Bio-compliant inputs is a natural consequence of trying to reduce environmental impact on a global scale.
To put it somewhat bluntly, being Bio rarely imposes substantial, day-to-day constraints on winemaking operations. That is the practical reality in most cases.
The “Natural” Definition That Never Really Existed
“Natural,” “natural wine,” “vin nature,” and shizen-ha wine (“natural-style wine”)—there are many labels, but in this article I generally use “natural” and “natural wine” with the same meaning.
The complication, as the rather careful phrasing in the previous sentence suggests, is that these terms are not used consistently. Different people use “natural wine” to mean different things.
The root cause is straightforward: for a long time, there was no widely accepted, official definition of “natural wine” issued by a public authority.
Without a definition that has been formalized by a public body and broadly endorsed within the trade, it is impossible to standardize usage. As a result, understanding and mental images differ from one person to another, and the way the term is used is unstable. This is one of the reasons “natural” has turned into a vague, image-driven word with no clearly defined content.
It is also worth noting that “orange wine” is frequently, but incorrectly, assumed to be a type of natural wine. In reality, orange wine is, in very simple terms, “white wine made with skin contact, following red-wine-style maceration.” Whether a wine is Bio or natural has no inherent connection to whether it is an orange wine.
A Trade Journal’s Provisional Definition of Natural Wine
Within the wine trade, there have been attempts to define natural wine. One wine trade magazine, for example, proposed its own definition of “natural wine,” and I will use that as a reference point in this article. It is important to stress, however, that this definition was developed by a private publisher and is not an official standard, nor is it universally adopted in the industry.
I discuss the details in another article (“I Thought Natural Wines Weren’t Sweet? Part 1”), so here I will only extract the key elements and recast them as connected prose instead of listing them verbatim.
First, the definition requires that grapes be grown under organic or biodynamic viticulture. Certification itself is not treated as an absolute requirement, but rather as something that is “desirable” or recommended.
Second, the grapes must be hand-harvested, not picked by machine.
Third, fermentation must be carried out exclusively by wild (indigenous) yeasts, without the addition of active dry yeast.
Fourth, winemaking inputs are restricted: enzymes may not be used, and no additives other than sulfur dioxide (SO₂) are permitted.
Finally, the total SO₂ content must be kept at or below 70 mg/L (the original text uses “ml/l,” which is understood here as mg/L). Wines must also be produced without fining or filtration, and without the use of advanced physical processing equipment such as reverse osmosis or spinning cone columns.
In short, this trade-journal definition assumes that natural wine must be based on organic or biodynamic viticulture as a minimum requirement, and then places relatively strict constraints on the winemaking side.
The INAO Definition and the Premise of This Article
In March 2020, the French authority INAO (Institut National de l’Origine et de la Qualité) adopted an official definition relating to natural wine. I discuss that in detail in a separate article, “The Definition of Natural Wine and What It Implies.”
The content you are now reading, however, is based on the situation before the INAO definition was adopted. Please keep that temporal context in mind.
The Spread of “Doing Nothing Is Natural”
If we look again at the provisional definition published in the trade journal, it is striking how many of the key conditions are formulated in the negative: “not used,” “do not exceed,” “not performed,” and so on.
These negative phrasings have often been misunderstood and then further over-interpreted, and it is on that misunderstanding that much of today’s perception of natural wine seems to rest. Importantly, this misunderstanding is shared not only by consumers but also by many producers. It might even be more accurate to say that producers interpreted the definition in that way, communicated it accordingly, and consumers were “educated” by that messaging.
This misunderstanding can be summarized quite succinctly:
“Doing nothing is natural, and that is what it means for a wine to be ‘natural’.”
The reasoning goes something like this: if the definition says certain things are “not used” or “not done,” then surely the most natural approach is to interfere as little as possible—let the vines grow “naturally,” let fermentation proceed “naturally,” and refrain as much as possible from intervening.
At first glance, this seems plausible. From an enological standpoint, however, the argument is fundamentally flawed.
Nonetheless, this notion of “natural” easily slides into the label “natural-style” (shizen-ha) and then is reattached, almost without friction, to the term “natural.”
As a result, many wines marketed as natural wine today are effectively made—and understood—under this misdefined principle of “doing as little as possible.” I explore this situation in more depth in another article, “Is Quality Management Unnecessary in Wine? The Risk of a Lawless Grey Zone in Half-Baked ‘Natural-Style’ Production.”
Originally, the trade journal’s definition rested on the concept of “nature under control.” In contrast, the way “natural-style” is currently understood and practiced is much closer to uncontrolled or unmanaged nature. There is a substantial gap between these two approaches, and that gap is a major driver of the ongoing confusion around natural wine.
“Good Natural Wine” as Controlled Nature
In a previous post, I wrote the following about natural wine (paraphrased here):
Just to be clear, there are producers who make excellent wines under what is commonly called “natural” or “natural-style.”
However, I often find that the producers I consider to be truly good are not necessarily the ones that self-identified natural-wine enthusiasts gravitate toward.
Taste is, by definition, subjective. It is impossible to generalize “deliciousness” across all drinkers.
Even so, if I state my own view explicitly, the natural wines that I personally find “good” are not those made according to the now-widespread natural-style notion of “doing nothing.” Instead, they are wines made in line with the original concept of controlled nature as outlined by that trade journal.
If I were to restrict this article to natural wines made strictly under that original definition, however, it would no longer address the concerns and questions that many people in Japan currently have about “natural wine.” To avoid that mismatch, I will proceed by clearly distinguishing the terms I use.
From this point onward, I will use the following terminology:
- Bio
Viticulture and winemaking conducted in accordance with rules defined in the EU organic certification framework. - Natural wine / Natural
Wines made under the trade-journal-style definition based on the concept of controlled nature. - Natural-style wine / Natural-style
Wines produced under the now common philosophy of “intervening as little as possible,” and the production approach itself.
I would ask you to read the remainder of this article with these definitions in mind, so that the terms are not inadvertently conflated.
Differences in the Winemaking Process and Their Implications
Winemaking consists of multiple stages. In this article, I focus on four stages where the differences between Bio, natural, and natural-style are especially apparent:
- Chaptalization
- Fermentation
- Stabilization
- Fining and filtration
Because the focus here is on cellar practices, I will not go into detail on viticultural differences.
Chaptalization
In this context, “chaptalization” refers to the addition of sugar (usually sucrose) to the must before or during fermentation in order to adjust the final alcohol content.
From a regulatory standpoint, none of the three categories—Bio, natural, or natural-style—strictly and universally prohibits chaptalization. In practice, however, the way it is treated differs.
Within natural and natural-style, there is a broadly shared perception that “chaptalization is not done.” This is often less about a legal rule and more about the idea that, if grapes are fully ripe, they should already have enough sugar and thus should not need chaptalization. There is a philosophical overlay of “adding nothing,” but the practical assumption about ripeness plays a major role.
By contrast, chaptalization is not particularly stigmatized in Bio. As noted earlier, the sugar used for chaptalization does have to be Bio-compliant, but beyond that, whether to chaptalize—and by how much—is left as a legitimate technical choice, depending on vintage conditions and target style.
If a natural or natural-style producer decides to chaptalize, and they do not hold Bio certification, there is no requirement that the sugar used must be Bio-certified. In that case, the choice of sugar is entirely at the producer’s discretion.
That said, because “no chaptalization” is a de facto expectation in natural and natural-style contexts, these wines tend to show lower alcohol levels in vintages or regions where ripeness is marginal.
In short: Bio freely recognizes chaptalization as a technical tool (within the limits of regional regulations), whereas natural and natural-style tend to avoid it for philosophical and image-related reasons.
Fermentation and Yeast Management
Fermentation and yeast selection are among the most critical points of divergence between Bio on the one hand and natural / natural-style on the other.
In Bio, the rules governing yeast are relatively limited. If cultured yeast is added, it must be Bio-compliant (i.e., produced under organic conditions), but there is no requirement to use wild (indigenous) yeast. Producers are free to choose whether to rely on wild yeast, cultured yeast, or a combination of both, and to design their fermentation strategy accordingly.
By contrast, natural and natural-style prohibit the use of active dry yeast, requiring fermentation to rely exclusively on wild (indigenous) yeasts. This effectively removes the option of selecting specific yeast strains to match grape composition, target style, or fermentation management needs.
Wild yeasts can contribute positively to aroma and complexity, but they also entail considerable risk in terms of fermentation kinetics and completeness. I address the benefits and risks of wild yeasts in detail in a separate article (“The Pros and Cons of Wild Yeasts”), so here I will simply note that fermentation management becomes significantly more difficult.
In spontaneous fermentation, it is impossible to predict in advance which yeast species or strains will dominate. One concrete risk is that a weakly fermentative yeast may become temporarily dominant, causing the alcoholic fermentation to stall.
Under normal circumstances, several interventions are possible—for example, inoculating a selected dry yeast strain to restart fermentation. However, in natural and natural-style frameworks where dry yeast is prohibited, this option is excluded from the outset.
Furthermore, it is common to add yeast nutrients to support a healthy fermentation. In many natural-style contexts, however, such nutrient additions are also avoided, not always because they are legally banned, but because they are perceived as inconsistent with the philosophy of “adding as little as possible.”
To summarize: Bio allows producers to combine cultured and wild yeasts as they see fit and to use yeast nutrients within defined limits. Natural and natural-style, in contrast, promote strict reliance on wild yeasts and strong pressure against nutrient additions, which increases the relative risk of fermentation problems.
Stabilization and Sulfur Dioxide (SO₂)
In this article, “stabilization” refers primarily to the addition of sulfur dioxide (sulfur dioxide, SO₂) after alcoholic fermentation in order to inactivate yeasts and other microorganisms and thus preserve wine quality. From an oxidative standpoint, SO₂ also plays a crucial role as an antioxidant.
I examine the multiple functions of SO₂ in detail in another article (“Do You Really Understand Sulfur Dioxide? Part 1”), and discuss dosing strategies and timing in “SO₂ Addition Levels and Timing in Wine Quality Management.” Here, I will focus on how SO₂ use differs between Bio, natural, and natural-style.
There is a very common misunderstanding that applies to both Bio and natural: many people believe that SO₂ additions are entirely prohibited in these categories. In reality, both allow SO₂ use, subject only to upper limits. The only category that consistently aims for “zero addition” is natural-style.
In broad terms, the maximum allowed SO₂ decreases in the order Bio → natural → natural-style.
In Bio, the upper limit for total SO₂ is defined by wine type (red, white, rosé, sparkling, etc.) and residual sugar level. In the trade-journal-style definition of natural wine, by contrast, total SO₂ is capped at a flat 70 mg/L, regardless of residual sugar. Many natural-style producers, for their part, aspire to no SO₂ additions at all (0 mg/L).
This has direct consequences for what kinds of wine can be stabilized reliably.
Because Bio sets different SO₂ limits according to wine style and residual sugar, it is practically feasible to stabilize a wide range of styles, from dry to sweet.
Natural wine, with its relatively low, flat cap on total SO₂, is effectively constrained to dry styles if a high degree of stability is required. Through rigorous filtration, cold stabilization, and other measures, it is theoretically possible to produce an off-dry wine with acceptable stability under this cap, but doing so demands extremely high technical precision.
In vintages where grape health is compromised or where fermentation has not gone well, even a dry wine may be difficult to stabilize adequately with a total SO₂ cap of 70 mg/L.
Natural-style wines, for their part, typically forgo SO₂ additions altogether, meaning that no deliberate microbiological stabilization is carried out.
For both natural-style and natural wines operating on minimal SO₂ margins, leaving residual sugar in the wine is inherently risky. Any remaining sugar can serve as a substrate for surviving microorganisms in bottle, leading directly to quality degradation.
In short: Bio offers relatively high flexibility for stabilization; natural is effectively limited to dry or near-dry styles if high stability is required; and natural-style, in principle, largely abandons stabilization.
Fining and Filtration
“Fining” refers to the addition of fining agents—such as enzymes, proteins, or bentonite—to remove suspended particles. “Filtration” refers to passing the wine through a physical filter in order to remove yeast and other fine particles.
These operations also highlight the differences between Bio and natural / natural-style.
In Bio, there are some restrictions on which fining agents and filtration methods may be used, but fining and filtration as such are allowed. In red wines, some producers choose an unfiltered style as a matter of personal philosophy, but this is not a requirement imposed by Bio regulations.
In natural and natural-style, by contrast, the trade-journal definition stipulates that fining and filtration are not to be used, and enzyme additions are likewise avoided in practice.
The implications are straightforward: wines are much more likely to be bottled with significant populations of viable microorganisms and suspended solids still present.
If stabilization has been carried out properly, this does not necessarily lead to immediate problems. However, as discussed above, natural wines operate under a relatively strict SO₂ cap, and natural-style wines often add no SO₂ at all. Coupled with the reliance on wild fermentation—and the corresponding higher risk of incomplete or sluggish fermentation—this increases the likelihood that some residual sugar remains in the finished wine.
- Microorganisms remain in the bottle and are not fully inactivated.
- Residual sugar is present in the wine as a nutrient source.
When both conditions are met, the outcome is predictable: microbial activity can resume in bottle.
Under Bio, a combination of fining, filtration, and SO₂ additions allows these risks to be controlled with relatively high certainty. In natural and especially natural-style frameworks, producers are choosing, to a significant extent, a set of practices that intentionally elevates these risks.
Conclusion: Winemaking as a Matter of Degree of Control
We have examined how Bio, natural, and natural-style differ at key stages of the winemaking process. A central concept throughout has been stabilization.
Stabilization can be described as the act of controlling natural change in order to manage quality. In this sense, it is sometimes framed as the opposite of “nature.”
At the same time, stabilization is also a direct measure of the degree of quality control.
If one aims to maintain quality up to the moment the wine is poured into the drinker’s glass, the degree of stabilization—and thus of control—inevitably increases.
For Bio wines, this is not particularly problematic. Across fermentation, stabilization, and finishing, all the tools needed to maintain a high level of quality control and stability are available, within the defined regulatory framework.
For natural wines, the situation is more demanding. Nevertheless, by enforcing strict control at every stage and carefully balancing the trade-offs between interventions, it is theoretically possible to achieve high stability and high quality simultaneously. The difficulty is that, if something goes wrong at any one stage, it becomes extremely hard to compensate at another. In effect, the required technical level and vigilance are both very high, and the margin for error is small.
Natural wines that clear all of these hurdles and reach the market in sound condition are clear evidence of the producer’s technical skill and uncompromising approach, and they are fully deserving of recognition.
Natural-style wines, by contrast, are positioned almost at the opposite end of the spectrum from stabilization.
It is certainly possible that, by a fortunate alignment of factors, a very good wine is produced. However, such success is essentially coincidental; it does not guarantee reproducibility or consistency. In some cases, even within the same lot, bottle-to-bottle variation may arise depending on the timing of opening and storage conditions.
Of course, even within “natural-style,” there is considerable diversity among producers. Approaches to “how far to control” differ, and it would not be fair to judge all producers by a single template. Still, the core philosophy of distancing oneself from stabilization and control appears to be widely shared.
My own view, stated plainly, is that winemaking is fundamentally about quality management.
Quality management, in turn, is about keeping the degree of stabilization at an appropriate level. Put differently, the essence of winemaking is “taking responsibility for delivering a wine of stable quality all the way to the consumer’s glass.”
In a purely technical sense, making “wine” is not particularly difficult. Crush grapes and leave the must alone, and it will ferment spontaneously and produce an alcoholic liquid.
What is absent in that scenario, however, is any form of quality management, or any enological meaning of “winemaking.” It is simply an uncontrolled natural process. If some proponents of natural-style wine insist that viticulture and enology are unnecessary, the endpoint of that logic is very close to this uncontrolled scenario.
Can we genuinely call the style I have referred to as “natural-style” in this article “winemaking”?
And, more importantly, is the rise of this natural-style movement unfairly damaging the reputation of natural wines that are made with a high degree of control and care?
I hope this article helps not only to clarify the differences between Bio and natural wine, but also to dispel some of the misunderstandings currently surrounding natural wine.
