Brut is the most common style of modern Champagne by sugar level.
Brut Champagne contains no more than 12 grams of sugar per litre under the traditional European classification. The sugar is normally added as dosage, also called liqueur d’expédition, after disgorgement. Dosage balances acidity and helps determine the wine’s final style.
The Champagne sweetness scale runs from brut nature and extra brut through brut, extra dry, sec, demi-sec and doux. Despite its name, extra dry is sweeter than brut, while doux is the sweetest category. These labels describe residual sugar, not whether the wine tastes harsh or fruity.
Brut does not mean completely sugar-free. Brut nature, also called zero dosage in some contexts, has the lowest sugar level. Champagne’s high natural acidity can make a wine taste drier than its measured sugar content suggests.