From prosecco to pet-nat, Cava to Champagne – learn the art behind your favourite sparkling wine.
Whether you’re a lover of prosecco, Champagne, or pét nat, it’s important to know that not all sparkling wines are created equal. One thing they do all have in common: they contain carbon dioxide (AKA CO2). That’s what gives them their delightful fizz (it’s not called “bubbly” for nothing), and differentiates them from still wines.
There’s five major ways to get bubbles in the bottle, each producing different carbonation levels and finished products. Below, we dig into the highlights of each, starting with the most famous of the lot.
- Traditional method
- Transfer method
- Ancestral method
- Carbonation
- Tank method
Considered the Rolls Royce of sparkling methods, the traditional method, or méthode traditionnelle, is the technique used in the Champagne region of France to produce, you guessed it, Champagne. It was invented in England around 1650, before being thrust into stardom by French Benedictine monk Dom Perignon around 1700.
While plenty of places around the world follow the traditional method, the term Champagne is legally protected by the French. This means you can’t call just any bottle of sparkling wine ‘Champagne’ – it must come from the Champagne region. Spanish winemakers therefore call their traditional method sparkling wines Cava, while here in Australia we label ours everything from ‘sparkling wine’, to the specific grapes used, to méthode traditionnelle.
This method is the most widely used and it’s synonymous with quality. While it’s an intensive, time-consuming process, and certainly the most costly, it produces some of the best wines out there (yep, I’m talking about that exxy bottle of Dom Perignon you’ve been eyeing off). Many credit this method with creating the highest quality, longest-living, and most complex sparkling wines possible.
So, this is how it rolls – in five steps.
1. It begins with the base
In short, grapes are harvested and pressed, the juice goes into a tank, primary fermentation runs its course and you end up with a base wine. (Of course you can read our full run-down on how white wine or red and rosé wine is made if you want the full detail.) The winemaker takes the various base wines and blends them together into what the French call a cuvée – basically the final mix of wines that will feature in the sparkling.
Now, depending on where you are in the world, the grapes used in this base wine can vary. Some regions, like Champagne, enforce strict rules around what grapes can and can’t be used – Champagne can only be made from a combination of chardonnay, pinot noir and pinot meunier. Those of you who know your grapes will note that pinot noir and pinot meunier are indeed red! But in the case of Champagne, only the juice from the grape’s flesh is used (the colour of a wine comes from the skins).
Beyond Champagne, all sorts of grapes find their way into bottles of bubbly – everything from semillon to chenin blanc, riesling to trebbiano. In Australia you’ll find plenty made from red grapes like shiraz, merlot and cabernet sauvignon.
2. Time for a secondary bottle fermentation
The cuvée goes into a bottle, along with added yeast and sugar (known in the biz as liqueur de tirage. It’s then sealed with a bottle cap to keep all that soon-to-be fizz inside. Over the next four to six weeks, a secondary fermentation takes place. As the yeast feeds on the sugar it produces carbon dioxide (CO2), thus creating the bubbles we know and love.
3. Creating flavour with lees ageing
Once secondary fermentation wraps, the yeast forms a sediment in the bottle, known in the industry as ‘lees’. This is what gives Champagne its killer flavour profile – think freshly baked biscuits, toasted bread and nuts. The longer the wine rests on the lees, the stronger these flavours become. Champagne requires a minimum of 15 months of ageing, or 36 months to be given the title of ‘vintage Champagne’.
4. It’s time for a little riddling and disgorging
While lees are great for building flavour, that sediment has got to come out of the bottle before it hits the shelves. Riddling is the process of tipping the wines upside down, gently moving the sediment down to the neck of the bottle so it’s easier to remove.
Next comes a clever process called ‘disgorging’. The necks of the bottles are plunged into freezing liquid, solidifying the lees. The caps can then be flicked off and, thanks to the pressure from the CO2, the frozen plug of lees shoots out of the bottle.
Traditionally riddling and disgorging was done by hand, but these days it’s more often handled by purpose-built machines.
5. A bit of dosage, darling
Before the wine is corked, it's topped up with what’s known as ‘dosage’ (pronounced fancily as ‘do-saaajjje’). Essentially this is just some form of sweetness (sugar, or a mixture of wine and sugar) added to the Champagne to balance it out. Certain sparkling grapes can struggle a little to ripen, meaning the resulting wine can be overly acidic. Dosage acts as a simple corrective measure, with the winemaker deciding how much sweetness should be added to the wine, depending on whether they want an extra dry, dry, semi-dry or sweet sparkling.
With the wine now at the perfect blend of flavours, the bottle is resealed with a cork and labelled.
Many Aussie sparklings make use of this method as it’s far simpler, but still produces high-quality wines. Sometimes this will translate into lower prices – a simpler process also means a cheaper one – a saving that can be passed on to the consumer.
If you like your bubbly complex and expensive, the traditional method is the place to start. But if you’re looking for the OG, the ancestral method is where it’s at. The oldest technique of the lot, it’s also one of the simplest – and the one used to make pétillant naturel (AKA pét nat).
Fun and sometimes funky, these beauties are done and dusted in one single ferment. The wine starts off the regular way, but gets bottled before the primary fermentation is complete. That way the wine continues to ferment after it’s been bottled and capped. With the right timing, a winemaker can produce a playful bottle of fizz without the hoo-ha of other methods. It might not have the same long-aged nuanced flavours of Champagne, but it sure does go down well at a picnic.
We like to think of the tank method (also known as the charmat method) as a happy medium. When a rich, complex style of Champagne isn’t what you’re after (or isn’t in your budget), the tank method may come to the rescue.
Resourceful Italian winemaker Federico Matinotti developed the method in 1895 as a faster way to create high-quality sparkling. Refined by Frenchman Eugene Charmat in 1905 (who also patented the idea), the process is different to the traditional method in that secondary fermentation occurs in tanks rather than the bottle. Long story short: winemakers make a base wine (during which the first fermentation takes place), pop it into stainless steel tanks, and add the liqueur de tirage (sugar and yeast) to kick off secondary fermentation. Once that’s complete, and there’s plenty of delicious bubbles kicking about, the wine is filtered and bottled.
The tank method only takes between two and six weeks – much faster than its traditional counterpart – and is used to make prosecco, AKA the backbone of Aperol Spritzes.
