Sparkling wines are wines with significant carbon dioxide that makes them effervescent or bubbly. There are four main methods to produce sparkling wines - the Champagne method, Transversage method, Charmat/tank method, and carbonation. The traditional Champagne method involves a secondary fermentation in the bottle that produces the bubbles. Champagne has strict regulations around production methods and grape varieties used. Sparkling wines from other regions use different techniques but may be modeled after Champagne's prestige and quality.