Natural winemaking: how the wine is made, from the tank to the BIB | LET IT BiB
There is a lot of talk about what natural wine is not—no industrial yeasts, no sulfur, no additives. But what actually happens in a natural winemaker's cellar, between the harvested grapes and the wine in your BIB? Every step of natural winemaking is a choice: deliberate and precise. Here is how it happens, without the jargon.
Step 1: Sorting at the winery
The grapes arrive at the winery after being harvested by hand—mostly in whole bunches, in 15 to 20 kg crates to prevent crushing. The first operation is table sorting: the pickers (or the winemaker alone) review the bunches one last time, remove any damaged, burst, or underripe berries, and discard leaves and vegetal debris.
This sorting process, which may seem anecdotal, is actually crucial. A single rotten bunch in a vat can contaminate the entire fermentation with undesirable bacteria. In natural wine, with no sulfur to stabilize, a questionable grape is a real risk. The quality of the wine starts here, long before the tank.
Step 2: Crushing or pressing
Once the grapes are sorted, the winemaker must decide how to extract the juice. There are several options, depending on the type of wine they aim to produce:
- Whole bunches in the vat (carbonic maceration): whole bunches are put into the tank without being destemmed or crushed. Fermentation begins inside each berry, which results in very fruity, low-tannin wines with floral aromas. This is the emblematic method of Beaujolais and many light natural reds.
- Destemming followed by gentle crushing: the stems are removed, the berries are lightly crushed to release the juice, then everything is put into the tank with the skins (maceration). For reds with more structure.
- Direct pressing: for whites and rosés, the grapes are pressed quickly after harvest to extract clear juice, without maceration with the skins. In natural wine, this pressing is always gentle—no excessive pressure that would extract bitter tannins or vegetal aromas.
- Long skin maceration for whites (orange wines): the white juice remains in contact with the skins for several days or weeks, as with a red wine. The result: orange wines, with their amber color and distinct tannins.
Step 3: Spontaneous fermentation
This is the heart of natural wine. Unlike conventional winemaking—where laboratory-selected yeasts are added to trigger and control fermentation—the natural winemaker lets the juice ferment using the indigenous yeasts already present on the grapes and in the cellar.
These wild yeasts are slower and less predictable than their industrial cousins. Fermentation can take weeks instead of a few days. The winemaker monitors temperatures, "remontages" (gently pumping over the juice to homogenize it), and smells. They intervene little, but they are constantly vigilant—a poorly monitored spontaneous fermentation can drift toward irreparable flaws.
The result of this slow process? More complex, less standardized aromatic profiles that vary from year to year depending on the yeasts present in the vintage. This is one of the reasons why natural wines are more "alive" and more different from one vintage to another than conventional wines. To understand why aromas continue to evolve even in the glass, our article why wine aromas evolve in the glass is enlightening.
Step 4: Malolactic fermentation
After alcoholic fermentation (conversion of sugars into alcohol), malolactic fermentation (or "malo") often follows: bacteria transform malic acid (acidic, sharp, like a green apple) into lactic acid (softer, creamier). This transformation softens and stabilizes the wine.
In conventional wine, malo is often artificially triggered to ensure it occurs before bottling. In natural wine, it happens spontaneously—or not at all, if the winemaker chooses to block it to preserve the wine's natural acidity. This decision profoundly influences the final style: a Loire white that has not undergone malo will be more tense and mineral; a white that has will be rounder and more buttery.
Step 5: Aging
Aging is the period between the end of fermentation and filling the BIB or bottles. It can last from a few weeks to several years, depending on the desired wine style. This is where the natural winemaker makes choices that are radically different from conventional methods:
- Stainless steel tank: neutral, does not alter aromas. Preserves freshness and fruit. Ideal for crisp whites and light reds intended for BIB.
- Amphora or terracotta jar: a return to the origins. Amphorae allow for very slow micro-oxygenation (like wood) without imparting oak aromas. Very trendy in natural wine.
- Old wood (barrels or oak vats): unlike new wood which imparts vanilla and toast, old wood gives off almost no more aromas. It only allows micro-oxygenation that refines tannins and gently stabilizes the wine.
- Concrete or concrete eggs: an inert material with interesting thermal properties (it maintains a stable temperature). Increasingly used in natural wine.
What you will never find with a natural winemaker: new barrels. New wood gives aromas of vanilla, coconut, and toasted bread that mask the expression of the grape variety and terroir—exactly the opposite of what a natural winemaker is looking for.
Step 6: Filling the BIB, without (or with very little) sulfur
Finally, the time comes to fill the BIB. This is often where the question of sulfur arises. The winemaker can choose to:
- Add nothing: the wine is bottled as is, with the sulfur naturally produced by fermentation (generally 5-15 mg/L). This is the most radical approach. The wine is alive, very lightly stabilized, and requires careful transport and storage conditions.
- Add a minimum of sulfur (10 to 40 mg/L total): a light protection that secures the journey and shelf life in the BIB without denaturing the wine. This is the approach of most serious natural winemakers.
The airtight bag of the BIB plays an important role here: by protecting the wine from oxidation between glasses, it partially compensates for the small amount of sulfur present. Our article why BIB protects wine better from oxidation explains this mechanism in detail.
Frequently asked questions about natural winemaking
How long does natural winemaking take?
From a few months to several years. A light natural Gamay, vinified by carbonic maceration and aged in stainless steel, can be in a BIB 4 to 6 months after harvest. A more structured red, aged in old wood, may wait 12 to 24 months before bottling. Patience is a cardinal virtue of natural wine—you do not rush what the wine is not yet ready to give.
Does natural winemaking always produce cloudy wines?
No. The potential cloudiness of a natural wine often comes from the lack of filtration—a deliberate choice, not an inevitable consequence of natural winemaking. A winemaker who lets their wine settle for long enough before bottling can obtain a perfectly clear wine without filtering. To understand when cloudiness is intentional and when it is a flaw, read our article cloudy or barnyard natural wine: flaw or character?
Can natural wine be produced in large quantities?
Yes, but it is rare. Natural winemaking requires constant monitoring and quick intervention when something goes astray. On a large scale, this vigilance is difficult to maintain. Most natural winemakers work on small plots (2 to 15 hectares), which allows them to oversee each tank personally. This is one of the reasons why natural wines often remain small-production products, harder to find than major conventional brands.