How is sparkling wine made?

I am pretty sure you like bubbly wines just as much as I do! But sometimes you wonder how are these fine bubbles are trapped in the bottle?  And maybe even when someone starts to talk about the methods of producing this sparkling wine, they use some words that you don’t really understand. Than don’t  worry, I am here to help you  understand better these words and the whole process behind the preparation of Champagne, Prosecco, Cava and all the other sparklings. I won’t go too deep into the details in this article, but if you are interested to know more, just reach out to me and I will be happy to share the rest!

First of all we have to stress that there isn’t just one way to make sparkling wine. Most of the times it happens during the second fermentation (the first one is when the still wine is made) because we need to ferment twice for the bubbles to come alive in the bottle.

With the

• Traditional Method (like Champagne, Cava, Crémant or Franciacorta just to mention a few)
• Tank Method (Prosecco, Lambrusco)
• Transfer Method (Small format (187 ml) and large format (3L+) Traditional Method sparkling wines)
• Ancestral Method (like the sparkling in the Loire Valley and Jura)

always have this second fermentation either in the bottle or in the tank. We need to add yeast again to start this process with some sugar which usually means that during this second fermentation the alcohol level will increase as well.

The only exception in our list is the Tank Method where this fermentation takes place in a temperature controlled tank and not in the bottle. When it is done, the sparkling wine is filtered to remove the dead yeasts and than bottled with the right amount of sugar and must.

But now let’s move back to 2nd fermentation in the bottle:

The most important aspect of the Traditional Method is that the transformation from a still to a sparkling wine occurs entirely inside the bottle.

And during that method we can already get familiar with some specific words for sparkling wine making:

Base Wine or “Cuvée”: grapes are picked (usually just a tinsy bit younger to preserve acidity) and fermented into a dry wine. Usually this dry wine has a lower alcohol level as during the second fermentation it will still increase and they want to keep it in control. The winemaker then takes the various base wines and blends them together.

Tirage: Yeast and sugars are added to the cuvée to start the second fermentation.

Second Fermentation: adds about 1.3% more alcohol and the process creates CO2 which is trapped inside the bottle. The yeast dies in a process called autolysis and remain in the bottle.

Aging: Wines are aged on their lees (the autolytic yeast particles) for a period of time to develop texture in the wine. Most believe the longer the wine ages on its lees, the better.

Riddling: Clarification occurs by settling the bottle upside down and the dead yeast cells collect in the neck of the bottle.

Disgorging: Removing sediment from bottle. The bottles are placed upside down into freezing liquid which causes the yeast bits to freeze in the neck of the bottle. The crown cap is then popped off momentarily which allows the frozen chunk of lees to shoot out of the pressurized bottle.

Dosage: A mixture of wine and sugar is added to fill bottles and then bottles are corked, wired and labeled.

With Transfer Method after aging the sparkling wine is tranfered into high pressured tanks for filtering and removing the dead yeasts and then when it is back into the bottle will get the dosage.

The Ancestral Method uses icy temperatures (and filteration) to pause the fermentation mid-way for a period of months and then wines are bottled and the fermentation finishes, trapping the CO2 in the bottle. When the desired level of CO2 is reached, wines are chilled again, riddled and disgorged just like the traditional method, but no dosage is added.

Now we covered the main production methods using second fermentation but I have left the one with only one fermentation at the end: the Asti Method.

The one which only had one fermentation in the making of bubbles, let’s see how it’s done:

The must is chilled so it does not start fermenting, and is stored until needed. (It is fermented to order to create a fresh, new batch.) Later, when needed, must is warmed and fermentation starts. Initially, carbon-dioxide is allowed to escape. Partway through, the tank is sealed to retain CO2. Then the fermentation is stopped early (by chilling the wine) at 7-7.5% alcohol level, so the wine is left sweet (with unfermented sugar) and at the end the wine is filtered and bottled.

This method is mainly used in Piedmont, Italy for the production of Moscato d’Asti but I am pretty sure we can taste some sweeter style sparklings made with the Asti method from a different part of the World. If you had one, please let me know, I am keen to try some!

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