Disgorgement leaves a void in the bottle that must now be filled. Dosage (a mixture of pure cane sugar and old Champagne wine) is normally added at this stage to balance the naturally high acidity of the wine. The amount of dosage or liqueur d’expédition added determines how sweet the finished wine will be, whether ’Extra-Brut’, ’Brut Nature’, ’Brut’, ’Extra-Dry’, ’Sec’, ’Demi-Sec’ or ’Doux’.
The dosing liquor is prepared several months in advance using reserve wines at least two years old, which are carefully filtered to eliminate any yeasts or bacteria that might trigger an unintended fermentation.
Adding sugar is the means to create the different categories of Champagne, which are classified as defined by EU regulations, in ascending order of sweetness as follows:
Certain wines contain no dosage at all. In which case, the void created by disgorgement is filled by wine identical to the wine in the bottle. Such wines may be called ‘Zero Dosage’, or ‘Brut 100% (or ‘Brut Intégral’ or ‘Brut Sauvage’) etc.
Historically, Champagne contained much more dosage than it does today. Tastes have evolved, and today’s consumer prefers drier wines, probably because the richness of a modern diet requires less sugar to go with it. The colder Scandinavian countries are the last to favour the sweet, Doux and Demi Sec styles of Champagne. The Russians remained Champagne’s biggest market until the revolution in 1917 and only drank sweet Champagne wines. The Americans meanwhile preferred dry Champagne while the English chose Extra-Dry and Brut. As a result, it was the practice for many years to adjust dosage to suit each national market – catering to the so-called goût russe, goût américain and goût anglais. These days however the level of dosage is fixed and clearly stated on the label.
Dosage in technical terms – the addition of between 0 and 5-6cl of liqueur d’expédition to the disgorged bottle – is performed with an automatic or semi-automatic machine called the doseuse (dosage machine). The efficiency of these machines depends on the size of business, the best of them handling slightly more than 18,000 bottles per hour, following a three-step process:
The bottles are then moved immediately to a corking machine alongside the doseuse, where they are hermetically sealed with a best-quality cork stopper, held in place by a wire hood. This provides for a tight seal, making sure the Champagne holds onto its bubbles.