How sparkling wine is made
I’m a big fan of sparkling wine. I have a fair degree of empathy with Lilly Bollinger who is reported to have said, “I drink Champagne when I’m happy and when I’m sad. Sometimes I drink it when I’m alone. When I have company I consider it obligatory. I trifle with it if I’m not hungry and drink it when I am. Otherwise, I never touch it―unless I’m thirsty.” The blend of refreshing acidic wine and luxurious twist added by the bubbles makes sparkling wine feel like a treat whatever the occasion.
But how do those bubbles get there in the first place? Well, the process is actually so complex that I’ve created a mini-series on the various methods of making it (see here). So for now, we’ll just focus on the basics.
The style of wines which suit bubbles
The vast majority of sparkling wine is white. There are of course, rose, red and even orange sparkling wines. They represent a relatively small proportion of overall production. Of course, just because the final wine is white, does not mean that red grapes we not used in its production. Two of the three champagne grapes are in fact red varieties.
Perhaps one of the reasons white wine lends itself well to the production of sparkling wine, is because it tends to be on the more acidic end of the spectrum. By far the most common sparkling wine grapes are Chardonnay and Pinot Noir. Although the popularity of Prosecco likely means that the Glera grape probably deserves an honourable mention.
How do the bubbles get there
If we think about the fermentation process, we know that sugars are turned into alcohol by yeast. During this process, we also get some other flavour producing compounds added to the wine. Also some heat is produced, and also carbon dioxide is generated. During the process of making a still wine, the carbon dioxide is released and is treated like a waste product. Winemakers have to be careful during certain winemaking processes not to pass out from a lack of oxygen.
Now if we were to prevent that carbon dioxide from escaping the vessel the wine is fermenting in, it dissolves into the wine. In doing so it will make it sparkling. Essentially, this is the process of making a sparkling wine in a nutshell. At what stage in the wine’s production the carbon dioxide is trapped depends on the method being used.
Other production processes and bottling
Given the vast variety of methods of making sparkling wine, I won’t cover every wine making option here. One of the big differences between key types of sparkling wine is whether any of the secondary wine making processes we explored earlier in this series are used. Sparkling wines are often left to rest on the dead yeast cells (the lees) which impact yeasty, bready, biscuity flavours into the wine. This is especially true of champagne.
When people talk about Champagne having a brioche-y flavour, this is what they are referring to. Some sparkling wines will also potentially be made of base wines which are oak aged. Others have undergone malolactic conversion (although retaining acidity is usually desirable).
What is very common in sparkling wine making is blending wines of different varieties together. These base wines tend to bring different properties to the final wine creating balance. If you ever get to do a vertical tasting (a tasting of different types of the same wine) of champagnes, you will be able to see if you can detect the difference between champagnes made with predominantly Chardonnay, those with greater quantities of Pinot Noir, Meunier or other varieties.
Bottling methods depend on the method used, but all that CO₂ creates a lot of pressure in a bottle. Sparkling wine bottles have to be made of stronger and thicker glass to contain that pressure. The cork is also secured in place using a wire cage in most cases. This is to stop it from shooting out under the pressure.
If you want to know more about the different methods of making sparkling wine, do check out my mini-series on these methods. But whether you are a fan of Prosecco, Champagne, English Sparkling wine or another style of bubbly, next time you try one, you’ll be able to explain to everyone how the bubbles got there! In the meantime, keep exploring this beautiful planet we live on, one glass at a time!