We all know when we’re drinking a sparkling wine because of the bubbles, but not all sparkling wine is Champagne and not all is made the same way.
The bubbles that form when a bottle is opened are carbon dioxide that has been in solution. How that carbon dioxide got into the wine is the story of how sparkling wine is made.
The four ways are by injection, and the tank, transfer or traditional methods.
Injection means just that: CO2 is pumped into the bottle of wine. This is how bubbles get into carbonated soft drinks. It’s the cheapest way of adding fizz.
The remaining three methods all get their bubbles through inducing a second fermentation in wine in a sealed container. Yeast and a little sugar is added, the yeast eats the sugar creating carbon dioxide that cannot escape so remains in the wine. When all the sugar is consumed the yeast, which has multiplied during its short life, dies leaving a gritty grey residue of dead yeast cells behind.
If you make the second fermentation in the bottle, like they do in Champagne in the traditional method, then you have the challenge of removing the dead yeast. In the traditional method the bottle is upturned so the dead yeast cells fall down the neck onto the closure. The neck is frozen and the bottle opened. The pressure forces out a plug of ice containing residue, the bottle is topped up with wine and a new cork inserted.
It is labour intensive and expensive, but that is the traditional method used in France for Champagne. Other places that can’t call their wines Champagne use the term methode traditionelle, or traditional method and some state on the label ‘fermented in this bottle’. Note that ‘this’, it’s an important distinction from the following method.
The transfer method bypasses freezing the neck and opens the bottle to pour the contents through a filter to catch the sediment and into a new bottle. Such wines sometimes state ‘Fermented in the bottle’, which is true but it is not fermented in the same bottle the wine is sold in. Transferring between bottles loses some of the pressure and bubbles.
In the tank method, Cuve Close in French and also called Charmat after the man that invented the process, wine enjoys its second fermentation in a huge tank, the sediment falls to the floor and the wine is bottled under pressure. This is an inexpensive method that produces an acceptable fizz.
When you buy a bottle of fizz the label should make it clear how the bubbles came about. Method Traditional wines include Champagne (from France), Cava (from Spain) and Cap Classique (from South Africa. Tank method wines include Prosecco and Asti (from Italy).
It is commonly accepted that the best fizz has tiny bubbles and that the smallest bubbles are made by the traditional method. But recent research suggests that the grape varieties in the wine, the yeast used for fermentation and the length of time the wine rests on the dead yeast cells all play a part in determining bubble size.
Me? I love sparkling wine and I drink Champagne most weeks but I also love Cava and Prosecco and sparkling wines from anywhere. And although I believed that CO2 injected wines were inferior I recently enjoyed a sparkling J C LeRoux Sauvignon Blanc made by that method that had tiny persistent bubbles as good as any Champagne.
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