How Is Sparkling Wine Made: Master Class In Bubbles

Making sparkling wine is probably the most technically demanding thing you can do in a winery.

It’s not just about bubbles. It’s about controlling pressure without explosions, managing two fermentations instead of one, and somehow ending up with something elegant rather than a fizzy mess. The fact that monks figured this out in 1531 (accidentally, while trying to make still wine) is nothing short of a miracle.

What Makes Wine ‘Sparkling’?

At its core, sparkling wine is still wine with dissolved carbon dioxide. But that simple definition undersells the transformation.

Still wine is complete after one fermentation. Sparkling wine demands a second fermentation specifically to create and trap CO2. This isn’t just carbonated wine (though that unfortunate method exists). True sparkling wine integrates bubbles through fermentation, creating a completely different sensory experience.

The bubbles do more than tickle your nose. They carry aromas more efficiently, change the wine’s texture, and even affect how we perceive sweetness and acidity. A base wine that tastes sharp and austere transforms into something festive and refined once it sparkles.

That transformation requires radically different winemaking decisions from day one…

The Science Behind the Sparkle

Here’s what creates those bubbles: yeast eating sugar and producing CO2 as waste. Simple chemistry. But trap that CO2 under pressure – whether in a bottle or tank — and it dissolves into the wine. Pop the cork, pressure drops, CO2 comes out of solution. Bubbles.

The magic is in the details.

Pressure matters more than most people realize. We measure it in atmospheres (bars) above normal air pressure:

• Beady: Less than 1 bar (15 psi) barely there bubbles

• Semi-sparkling: 1-2.5 bars (15-36 psi) think Prosecco frizzante

• Sparkling: 3+ bars (44+ psi) the real deal

Most Champagne sits at 5-7 bars. That’s roughly 90 psi. Same pressure as a truck tire.

The Foundation: Base Wine

Every sparkling wine starts as a still wine.

And this is where things get counterintuitive.

You want grapes that would make terrible table wine – high acid, low sugar, barely ripe. In Champagne, they pick at around 17-19° Brix* (compared to 24° for most still wines). The resulting base wine tastes like battery acid. Around 10% alcohol. Mouth-puckeringly tart.

* Brix is simply a measurement of sugar content in grape juice (or any liquid).

The fermentation happens just like any white wine – in stainless steel tanks or oak barrels. Temperature controlled. Usually quick and clean. Some producers let malolactic fermentation happen (softens the acid), others block it completely. Depends on the style they’re after.

Then comes blending. Or “assemblage” if you’re feeling French. This is where winemakers earn their keep, mixing different grape varieties, vineyards, even vintages to create the house style. A typical Champagne blend might include 30-50 different base wines.

Method 1: Traditional (The Champagne Way)

The traditional method turns winemaking into a bottle-by-bottle obsession.

Step 1: Tirage
Mix base wine + sugar + yeast + nutrients. The exact sugar amount determines final pressure — 24 grams per liter gives you about 6 bars. Too little? Flat wine. Too much? Exploding bottles. (Early Champagne houses lost up to 90% of production this way.)

Fill bottles. Crown cap them. Stack horizontally.

Step 2: Second Fermentation
Takes 6-8 weeks. Creates roughly 1.3% more alcohol and all that CO2. The yeast dies when it runs out of sugar, creating “lees” — dead yeast cells that settle along the bottle’s side.

Step 3: Aging on Lees
This is where time becomes an ingredient. Minimum 15 months for non-vintage Champagne. Three years for vintage. Some houses age for a decade or more.

What happens during this time? Autolysis. The yeast cells break down, releasing proteins, lipids, and polysaccharides into the wine. This creates those brioche, toasted hazelnut, and mushroom notes everyone raves about.

Step 4: Riddling (Remuage)
Now you need those dead yeast cells out. Bottles go into A-frame racks called pupitres. Every day, someone turns each bottle 1/8 rotation while gradually tilting it downward. After 6-8 weeks, all the sediment collects in the neck.

(Modern gyropalettes do this in 3 days. Progress.)

Step 5: Disgorgement
Freeze the bottle neck in a -25°C brine solution. Pop the crown cap. Frozen yeast plug shoots out. You’ve just lost some wine.

Step 6: Dosage
Top up with “liqueur d’expédition” — base wine mixed with sugar. This determines final sweetness:

• Brut Nature: 0-3 g/L

• Extra Brut: 0-6 g/L

• Brut: 0-12 g/L

• Extra Dry: 12-17 g/L (yes, “extra dry” is sweeter than brut)

Cork it. Wire cage. Done.

The whole process takes years and requires handling each bottle multiple times. No wonder traditional method wines cost more.

Method 2: Tank Method (The Prosecco Way)

Eugène Charmat looked at the traditional method in 1907 and thought: “What if we just used a big tank?”

Brilliant.

Also called the Martinotti method (after Federico Martinotti who actually invented it in 1895 but had worse PR).

The process mirrors traditional method but happens in pressurized stainless steel tanks that hold thousands of liters. Base wine goes in. Sugar and yeast follow. Fermentation creates pressure. Filter out the yeast under pressure. Bottle under pressure.

Start to finish: 30 days.

The key difference isn’t just speed — it’s philosophy. Tank method preserves fresh fruit flavors. No extended lees contact means no bready complexity. For aromatic grapes like Glera (Prosecco) or Moscato, that’s exactly what you want.

Temperature control is critical here. Most producers ferment at 12-15°C to preserve those delicate aromatics. The best operations use specialized pneumatic presses that work under inert gas to prevent oxidation — even before fermentation starts, they’re thinking about freshness.

Method 3: Ancestral (The Original)

Before monks understood fermentation, they had a problem.

Wine, they bottled in fall would start bubbling come spring. Turns out, cold winter temperatures paused fermentation. Warming weather restarted it. Accidental sparkling wine.

Today’s ancestral method (pét-nat to hipsters) recreates this ancient accident on purpose.

Three ways to do it:

Interruption Method: Chill fermenting wine to near freezing. Bottle it with active yeast and remaining sugar. Let it finish in bottle. Requires perfect timing — bottle too early and you get bombs, too late and no bubbles.

Entr’acte Method: Ferment base wine dry. Add fresh grape juice. Bottle. Second fermentation from the new sugar creates bubbles. More control, less risk.

Overwintering: The truly traditional approach. Let wine naturally slow as cellar temperatures drop. Bottle in spring as it warms. Cross fingers.

Most pét-nats finish around 2-4 bars pressure. Gentler bubbles. Often cloudy (disgorgement is optional). Sometimes funky — those active yeasts can produce unexpected flavors.

The challenge? Consistency. Every bottle’s slightly different. That’s either charming or maddening, depending on your perspective.

Method 4: Transfer Method

Want a traditional method complexity without the hassle?

Enter transfer method.

Everything starts identically to traditional method — tirage, second fermentation in bottle, lees aging. But instead of riddling each bottle, you empty them all into a pressurized tank. Filter under pressure. Re-bottle under pressure.

Australia and New Zealand perfected this for good reason. It works brilliantly for small formats (splits) and large formats (magnums and up) where riddling becomes impractical.

The wine quality can match traditional methods. You get the autolytic complexity from lees aging. You just skip the labor-intensive riddling stage.

The Rogue Methods

Dioise Method

Exclusive to Clairette de Die in France’s Drôme Valley. Like ancestral method but with training wheels — fermentation is slowed by chilling, filtered to remove yeast, then finished in bottle with precise amounts of remaining sugar. More predictable than pét-nat, fruitier than traditional.

Continuous Method

Also called Russian method, because of course it is. Wine flows through a series of pressurized tanks containing yeast (sometimes on wood shavings for texture). Continuous fermentation, continuous flow. A month start to finish. Mostly used for Sovetskoye Shampanskoye.

Carbonation

The dirty secret. Inject CO2 into still wine. Like making SodaStream wine. Big, unstable bubbles that disappear fast. Legal in EU but must be labeled ‘aerated sparkling wine’. Used for supermarket specials.

The Equipment That Makes It Possible

Here’s what separates amateur hour from professional sparkling wine production:

Pressing defines everything that follows. Modern pneumatic presses operating under inert atmosphere prevent oxidation from the first moment grapes enter the winery. The gentle pressing cycles — some taking 3+ hours — extract juice without bitter phenolics from skins and seeds. Essential for sparkling wine’s delicate base.

Temperature control throughout fermentation and storage can make or break quality. Those base wines ferment cool. Second fermentation needs precise temperature management to control pressure buildup.

Bottling lines designed for sparkling wine handle entirely different physics than still wine equipment. You’re bottling under pressure, maintaining dissolved CO2, achieving consistent fill levels despite foam. The difference between a professional bottling line with proper counter-pressure fillers and trying to bottle carbonated wine on standard equipment? Night and day.

For smaller producers (and there are thousands globally), semi-automatic systems that handle everything from crown capping to cork insertion have democratized quality sparkling wine production. Companies like SRAML, who started supplying local producers, now equip boutique sparkling wine operations worldwide.

Reading the Clues

Want to know how your sparkling wine was made? Look for these tells:

Traditional Method Clues:

• “Méthode Traditionnelle” on label

• Fine, persistent bubbles

• Toasty, brioche notes

• Higher price point

• Vintage dates (often)

Tank Method Clues:

• Fresh, fruity aromatics

• Larger, more aggressive bubbles

• “Charmat” might appear on label

• Generally under $20

Pét-Nat Clues:

• Crown cap instead of cork

• Cloudy appearance (usually)

• Lower alcohol (often)

• “Pétillant naturel” or “méthode ancestrale”

• Unpredictable personality

The Reality Check

Making sparkling wine remains one of winemaking’s greatest technical challenges. Every method has its place. Traditional methods create complexity through time and autolysis. The tank method preserves freshness and fruit. Ancestral method offers rustic authenticity.

The best producers, whether they’re in Champagne or Valdobbiadene understand that great sparkling wine starts with the right equipment, the right fruit, and obsessive attention to detail at every stage.

Because in the end, those aren’t just bubbles.

They’re thousands of tiny decisions, perfectly executed, dancing in your glass.