Why do some wines have natural bubbles?

Bubbles in wine are often associated with Champagne or classic sparkling wines. Yet some wines develop their bubbles naturally, without added carbon dioxide or a controlled second fermentation. How is that possible?

This article explores natural sparkling wines, their production process, the impact of wine aging, and the importance of spontaneous wine fermentation in creating fine, natural bubbles.

Natural sparkling wines: a spontaneous phenomenon

IMAGE WITH URL [https://blog.liebherr.com/electromenager/fr/wp-content/uploads/sites/13/2019/02/vin-p%C3%A9tillant-1-721x400.jpg] GOES HERE

Unlike traditional sparkling wines made using precise methods, such as the Champagne method, natural sparkling wines are born from more natural processes.

These wines receive no added sugar or yeast after bottling. Their effervescence comes from spontaneous fermentation, which continues once the wine is bottled, naturally producing carbon dioxide.

The characteristics of natural sparkling wines

• They are often lightly filtered, giving them a slightly hazy appearance.
• Their bubbles are softer and more natural than those in classic sparkling wines.
• They offer raw, fruity aromas, sometimes with a fermentative edge.

These wines are also known as "Pét-Nat" (short for Pétillant Naturel), a name that highlights their authentic character and minimalist production method.

The key role of spontaneous fermentation

Spontaneous wine fermentation is essential to the formation of natural bubbles.

What is spontaneous fermentation?

Unlike controlled fermentations, where winemakers add selected yeasts to manage the conversion of sugar into alcohol, spontaneous fermentation relies solely on the yeasts naturally present on the grapes and in the winery environment.

As those yeasts begin turning grape sugar into alcohol, they produce carbon dioxide. If fermentation finishes after bottling, that gas becomes trapped in the wine, creating natural effervescence.

Why do some wines develop bubbles while others don't?

It all depends on several factors:

• Residual sugar levels: a wine bottled while fermentable sugars remain will develop bubbles.
• Fermentation temperature: a fermentation temporarily halted by cold can restart in the bottle.
• Native yeasts: some are more active and resilient, encouraging CO₂ production.

How wine aging influences effervescence

Wine aging also plays a role in whether bubbles are present.

Young, sparkling wines

Natural sparkling wines are generally enjoyed young, because their effervescence is often fleeting. Unlike Champagne or Crémant, which are crafted to age, these wines tend to hold onto their bubbles best when you drink them soon after production.

Aging and the loss of effervescence

Over time, carbon dioxide can gradually escape through the cork or interact with other components in the wine. The longer a natural sparkling wine ages, the more intensity it risks losing.

Some bottles also show a slight drop in pressure as the wine itself absorbs the CO₂.

The different categories of natural sparkling wines

Some wines develop bubbles naturally at different stages of production.

Ancestral-method wines

This method involves bottling a wine while fermentation is still underway.

• No sugar or yeast is added after bottling.
• Fermentation finishes in the bottle, producing a gentle sparkle.
• The result: fine bubbles and a more natural aromatic profile.

Lightly spritzy wines

Some still wines contain a small amount of natural CO₂ from fermentation. These are known as spritzy wines, or lightly sparkling wines.

Famous examples include:

• Muscadet sur Lie, which retains a slight spritz thanks to extended contact with the lees.
• Portugal's Vinho Verde, offering a fresh, lively sensation on the palate.

Sparkling wines from long fermentations

Some wines retain their natural bubbles thanks to a long fermentation in tank, which leaves a light sparkle in the bottled wine.

This style of production is common in certain wine regions where cool temperatures slow the fermentation process.

Why choose a natural sparkling wine?

Natural sparkling wines offer several advantages:

• Authenticity: they reflect the terroir and the winemaker's artisanal approach.
• Less intervention: fewer sulfites, no added commercial yeasts.
• Freshness and liveliness: their natural sparkle creates a pleasing sensation on the palate.

They're especially enjoyable as an aperitif, with seafood, or alongside light dishes.

How should you store a natural sparkling wine?

To preserve their effervescence, it's best to:

• Keep them cool: a stable temperature helps prevent the bubbles from fading.
• Store them upright: this limits the loss of carbon dioxide.
• Drink them young: they’re at their best in the first few years after bottling.

Once opened, a tight-sealing stopper can help keep them fresh for a day or two.

Conclusion

The natural bubbles in sparkling wines are the result of a spontaneous process, in which fermentation plays a key role. Thanks to spontaneous wine fermentation, wine aging, and native yeasts, some wines retain a unique effervescence without excessive human intervention.

Choosing a natural sparkling wine means embracing an artisanal approach, where terroir and the winemaker's know-how can shine through fully.

If you enjoyed this article, don't hesitate to read the next one, "Great German grape varieties to add to your collection", which might also interest you!