There are several ways to make sparkling wines. The most common way is by adding carbon dioxide to the wine, but there are other methods used by winemakers around the world.
The Champagne method, also known as the traditional method, is the most well-known way of making sparkling wines. In this method, the second fermentation of the wine is carried out in the bottle, producing carbon dioxide and giving the wine its distinctive bubbles. This process can take several years before the wine is ready to drink.
Another method that is often used is the Charmat method. In this method, the second fermentation is carried out in a large tank, rather than in individual bottles. This is a faster and cheaper way to make sparkling wines, but some winemakers claim it makes the wine less complex in flavor.
There is also the method of chilled fermentation, where the wine is kept at a low temperature during the second fermentation to slow down the process. This can help create a softer, finer bubble and add complexity to the wine.
Finally, there is the method of direct addition of carbon dioxide. In this method, carbon dioxide is added directly to the wine, without a second fermentation taking place. This is the fastest and least expensive way to make sparkling wines, but some winemakers claim that it reduces the flavor and complexity of the wine.
So, in general, there are several ways to make sparkling wines, each with their own advantages and disadvantages. Which method is best depends on the personal preference of the winemaker and the end consumer.