Sparkling wine is a style of wine characterized by the effervescence within, meaning the bubbles found in a liquid (Oxford Languages, 2020). Sparkling wines have carbon dioxide within them which is a result of the secondary fermentation process that happens either inside the bottle or in a pressurized tank (depending on what method of sparkling wine is used).
Sparkling wine can be produced through 6 major methods: the traditional, tank, transfer, ancestral, carbonation or continuous method. Each of these methods result in altering carbonation levels and thus create a different style of sparkling wine!
Méthode traditionnelle (Traditional Method)
The traditional method is likely to be the most common and known type of sparkling wine method due it being responsible for all our Champagne and Cava’s in the world. This type of sparkling wine method is also known for the quality of the wine it produces, but with high quality also comes a high price tag, making it the most expensive method out of the six. What makes this type of sparkling wine method so iconic, is the fact that the change from a still wine into a carbonated one, all occurs within the bottle.
The traditional method goes through a 7-stage process; base wine (‘Cuvee’), tirage, second fermentation, aging, riddling, disgorging and dosage.
When making a sparkling wine, the process always begins with a base wine which is when the grapes are harvested and fermented into a dry wine. If you have read our other blogs on the Verwood website, you may have read one about vintage wine. Now, within this blog, we stated what makes a vintage wine, yet we also explained how Champagne is made with it not being a vintage wine. This is because, to make a Champagne, the wine must be consistent in flavour, hence why a vintage one cannot be made (with them being grown and harvested within the same year and dependant on the year for the flavour profile). This is similar with most sparkling wines, as the base wine is that of several wines blended to give it the signature and consistent taste of a sparkling wine, like Champagne. The process of blending several wines together can also be referred to as a ‘Cuvée’.
The second stage consists of yeast and sugars being added to the cuvée to instigate the second fermentation process – this happens inside the bottle, where the bottles are topped with crown caps.
Within the second fermentation, an increase in alcohol content of 1.3% is created and the carbonation of the wine is a result of the CO2 trapped inside the bottle. The yeast dies during this stage in a process called autolysis, more commonly known as the lees, and remains in the bottle of which the sediment falls to the bottom.
The lees in the bottle are what age the wine and create texture. Different sparkling wines will age for certain periods of time, for example Champagne will age on its lees for a minimum of 15 months, unlike a Cava which can age for up to a minimum of only 9 months. This is essentially down to a winemaker’s preference as it can be said that aging a wine on its lees for longer periods of time, generally makes the quality of the wine taste better.
After the aging process has been completed, the clarification process can begin. For sparkling wines in the traditional method, this consists of settling the bottles upside down so that the dead yeast particles can collect in the neck of the bottle. They are then dipped into freezing liquid which freezes the collection of lees. The crown cap is then removed allowing the frozen chunk to shoot out of the pressurised bottle.
With the lees now removed from the bottle, there is less liquid, so a mixture of wine and sugar is added to the sparkling wine, ready for the wine to be corked, wired, and labelled.
Charmat (Tank Method)
The tank method, also known as the Charmat method, is commonly used to make Prosecco and Lambrusco wines. This method is very similar to the traditional method, though instead of using a bottle to ferment the wine a second time around, the Charmat method uses large tanks. These large tanks act in the same way as the bottle did in the traditional method, it just begins by adding base wines, yeast mixture and sugar into the tank, where the second fermentation takes place. Another differing feature in this method, is that there is a lack of aging as the wines are filtered and dosed immediately after the second fermentation process.
The Charmat method is one of which used by Verwood Estate Wines when making their special blend of Sparkling Chardonnay Pinot Noir. It has a toasty flavour with hints of custard apple and berries, leaving lingering flavours on the palate, characteristic of a sparkling wine produced through the Charmat method as they tend to have fresher tasting notes and stronger secondary flavours.
Another common type of sparkling wine method is the transfer method. This method is identical to the traditional method, though instead of riddling and disgorging the wine of the lees inside the bottle, the transfer method removes the lees through pressurised filters inside a pressurised tank. This happens after the second fermentation process has completed inside the bottle, where the wine is then emptied into the tanks in order to be filtered.
The ancestral method is said to predate the traditional method, hence ‘ancestral’. Depending on who you ask, the ancestral method varies enormously.
For many, the ancestral method involves a lack of the secondary fermentation process all together and that the wine is bottled prior to the completion of the first fermentation – this is a crucial point as there needs to be enough sugar in the wine to help create pressure and the iconic bubbles, however not too much so that the bottle is susceptible to burst. Apparently, ancestral wines tend to be softer in terms of the bubble content because of this bottling method. There is also a lack of disgorging of the wine meaning that there are often residual sugars and sediment left behind, making the wine appear to be cloudy.
Contrary to this, other experts state that the ancestral method uses freezing temperatures to pause the fermentation process, roughly half-way through for several months. The wine is then bottled where the fermentation process finalises and creates C02 inside the bottle. At its optimum level of carbon dioxide, the wines are chilled, and similarly to the traditional method, riddled and disgorged – the only other exception being that there is no dosage of wine and sugar added to the sparkling wine as a final step.
The carbonation method is a very simple type of sparkling wine method, commonly also referred to as ‘gas injection’. This method simply involves taking a still wine and carbonating it in a pressurised tank.
The carbonation method is one that has also been used by Verwood Estate Wines when producing the Sparkling Shiraz Rosé. This means that the still wine of Shiraz Rosé was put into a pressurised tank to create the carbonation in the Sparkling Shiraz Rosé.
Our Verwood Estate 2019 Sparkling Shiraz Rosé is similar to the 2019 Shiraz Rosé in that it has a stunning strawberry colour, cherry and red berry aromas and a smooth fruity crisp finish, difference being in that it has an added sparkle! This wine is perfectly paired with desserts for all the sweet tooth’s out there; strawberry pie being a great option!
The continuous method is also known as the Russian method due it being created by none other than the Russians!
This type of sparkling wine method involves constantly adding yeast into pressurised tanks during the second fermentation process (true to its name) – so much that the total pressure is usually equivalent to that of the traditional method when making Champagne. The wine is then moved into another tank, filled with yeast enrichments, so that the lees in the wine can attach to them, creating more texture and depth. The wine is then moved into a third and final pressurised tank where the yeast and enrichments are removed, thus leaving the wine prominently clear.