Cloudy or barnyard natural wine: flaw or character?
You open a natural wine: it's cloudy, it smells vaguely of leather or the stable, it fizzes a little. Is this normal? Is it intentional? Is it a flaw? The honest answer is: it depends on the wine and the winemaker — and no, it is not systematically "normal" just because it is natural. Here is how to tell the difference.
The initial misunderstanding: natural wine is not necessarily "weird"
Let's start by dispelling the biggest confusion around natural wine. A natural wine can be perfectly clear, clean on the nose, precise on the palate, without any unusual characteristics. Natural winemaking does not imply that a wine must be cloudy or smell animalistic.
What natural winemaking implies is the absence of technical interventions to mask what the grapes and fermentation provide. When the grapes are healthy, the fermentation is successful, and the storage is good, the result is often a wine of remarkable clarity and precision. A quality natural wine doesn't need to be strange to be natural.
What can be intentional and embraced
The haze or slight cloudiness
Some winemakers deliberately choose not to filter their wine before putting it in a BIB (bag-in-box) or bottle. The result is a wine with a slight haze — fine particles of yeast and pulp in suspension. Visually, the wine is a bit cloudy, but it is not unpleasant and does not affect the taste.
This haze can also appear in a wine that was once clear: it is often tartrate sediment or fine lees that have been resuspended after transport, a change in temperature, or opening the BIB. Shake it gently, let it rest for 30 minutes, and the wine becomes clear again. This is in no way a flaw.
Slight effervescence or "spritz"
Some natural wines have a slight effervescence — a few fine bubbles, a tingle on the tongue. This can come from a fermentation that is not quite finished at the time of bagging (residual malolactic fermentation), or from a deliberate choice by the winemaker to retain this liveliness. In a BIB, the airtight pouch can accentuate this phenomenon.
Is it a flaw? If it is subtle and adds freshness, no. If it is so pronounced that the wine seems "re-fermented" or the gas masks the aromas, yes, it is problematic. Context and intensity make all the difference.
So-called "animal" or "brett" aromas
This is the most debated point of natural wine. A wine can present aromas of stable, leather, sweat, or manure — this is what is often called Brettanomyces (or "brett"), a wild yeast present in many natural cellars. In small doses, brett can add a wild, spicy, animal dimension that some enthusiasts find exciting. In large doses, it crushes the fruit and makes it unpleasant.
Some natural winemakers fully embrace the brett in their cellars: it is part of their "signature." Others actively fight it. A very bretty wine is not automatically a "good natural wine" — it is often a sign of a lack of control in the cellar. The natural wine community is not unanimous on this subject, and that's a good thing.
What is a true flaw — and what should not be excused
Excessive volatile acidity (the "prick")
A natural wine made without sulfur is more vulnerable to acetic acid — which gives a wine a "prick" on the nose like vinegar. In very small doses, volatile acidity is normal and can even add complexity. Beyond a certain threshold, it is a recognized oenological flaw, not a characteristic of natural wine. A winemaker who does not master this parameter produces a defective wine, period.
Unintended oxidation
A white wine that yellows and smells of rancid butter, a red that takes on brick reflections and smells of cooked apple, in a wine that is not supposed to be made in an oxidative way — this is a flaw. Some natural winemakers embrace oxidative winemaking (as is the case with Jura "sous voile" wines, or some orange wines): in this case, it is intentional and documented. But a wine that has oxidized accidentally because the winemaker did not protect their tank properly is a flaw, not a style.
Cork taint (even in natural wine)
TCA (trichloroanisole) — the origin of "corked" taste — can affect any wine, natural or not. In a BIB, this risk does not exist because there is no cork. This is one of the subtle advantages of the BIB format: the airtight pouch eliminates this risk by design. To learn more, our article why BIB better protects wine from oxidation explains how the pouch works.
(Unintended) re-fermentation in the bottle
A wine that re-ferments in its container — because fermentation was not finished or because there was bacterial contamination — can become cloudy, acidic, flat, or unpleasantly fizzy. This is not at all the same thing as an intentional pétillant naturel. A wine that has re-fermented by accident is a defective wine.
How to tell the difference in your glass?
| What you observe | Potentially intentional | Potentially a flaw |
|---|---|---|
| Slightly cloudy wine | Yes (unfiltered) | If very intense cloudiness or thick sediment |
| Slight tingle on the palate | Yes (intentional residual fermentation) | If excessive gas or flat and acidic wine |
| Subtle animal aromas | Yes (slight brett, estate style) | If overpowering, masks fruit, unpleasant |
| Vinegar notes / "prick" | No | Yes (excessive volatile acidity) |
| Yellowed / pronounced brick color | If oxidative winemaking documented | Yes if non-oxidative wine (accidental oxidation) |
| Flat taste, no fruit | No | Yes (oxidation, re-fermentation, poor storage) |
The golden rule: context and the winemaker
To evaluate a natural wine correctly, the question to ask yourself is not "is this normal for a natural wine?" but "does this winemaker embrace this style and master it?" A slight haze in a wine from a winemaker who never filters and says so clearly: normal. The same haze in a wine sold as "natural wine" by someone we know nothing about: to be evaluated on a case-by-case basis.
This is why selection and trust in the estates count as much as the "natural" mention on the label. To learn how to read the information available on a label, our guide how to read a natural wine label helps you navigate.
Frequently asked questions
If I don't like a natural wine, is it necessarily a flaw?
Not necessarily. A wine can be well-made, without oenological flaws, and not be to your liking — because you don't like brett, or the very mineral style, or the lack of fruit. Taste is personal. What is defective is objectively detectable (volatile acidity, oxidation, unintended re-fermentation); what is stylistic is subjective. Both exist and are different.
What should I do if I think my BIB is defective?
Contact us. We only work with winemakers we follow closely, and if a wine has a real problem, we want to know about it. A defective wine remains a defective wine, regardless of the estate's philosophy. All contact information is on our contact page.
Is a "perfect" natural wine (clear, clean, without brett) less authentic?
Absolutely not. Authenticity in natural wine is not measured by the weirdness of the wine. It is measured by the sincerity of the winemaker's practices, the health of their vines, and their refusal of additives. A clear and clean wine, vinified without sulfur with indigenous yeasts from grapes grown biodynamically, is an exemplary natural wine.