Liqueur d’expédition in Champagne & Méthode Traditionnelle wines is the addition of a sweet liquid, used to determine the final level of sweetness in the finished Champagne or Sparkling wine. Immediately after disgorging (the removal of sediment from the bottle) but before the cork and muselet are added. The wine level is topped up with liqueur d'expédition, typically a sugar mixture, a practice also known as dosage.
Champagne Houses used to have a mysterious recipe or mixture of ingredients in their liqueur d'expédition: including port wine, cognac, elderberry wine, kirsch, framboise wine, alum solutions, tartaric acid and tannins. In days gone by, cognac was sometimes added if the wine was low in alcohol, but this practice is now very rare.
Typically today the dosage may consist of wine, sugar, brandy, ascorbic acid, citric acid, copper sulphate, plus 0.02 to 0.03 grams of sulphur dioxide as a preservative. As the sugar previously in the wine, was consumed during the secondary fermentation inside the bottle. A sweet dosage is added to balance the high natural acidity of Champagne, rather than to produce a sweeter taste. A ‘Brut’ style Champagne will only have a small amount of sugar added, and Champagne called ‘nature’ or ‘zero dosage’ will have no sugar added.
After the second fermentation has completed, and the wine has spent its desired time on yeast lees, it is time for the removal of the sediment, the disgorgement. This is achieved by immersing the neck of the bottle (after riddling) in a freezing brine solution, which freezes the sediment that has gathered in the neck. The pressure of the carbon dioxide expels the frozen pellet of dead-yeast, leaving the wine clear and pristine. A small amount of liquid is lost during this process and the wine will be topped up with the liqueur d’expedition and sparkling wine.
The younger the wine, or the shorter the ageing, the greater dosage of sugar required to balance its youthful acidity. High acidity is desired in Champagne as it keeps the wine fresh throughout its long period of production and also during any additional short-term cellaring by the customer. This acidity softens with age, so the older the Champagne the less dosage required. Sugar is added to nearly all Champagnes / Méthode Traditionnelle wines, because in the course of the second fermentation all the sugar is normally converted to alcohol and CO2, producing a far drier wine that is not to everyone’s taste. There is no chance of the wine undergoing a third fermentation in the bottle with the additional sugar, as all the yeasts is expelled at the time of disgorgement.
The actual sugar content will also depend on a desired wines style:
Extra Brut (0-6 grams/litre) = Bone dry.
Brut (0-12 grams/litre, as of July 2009) = Dry to very dry.
Extra Sec or Extra Dry (12-20 grams/litre) = Dry to medium dry.
Sec or Dry (17-35 grams/litre) = Medium to medium sweet.
Demi-Sec or Rich (35-50 grams/litre) = Sweet.
Doux (50+ grams/litre) = Very sweet, but this style is extremely rare.
For the production of ‘Vintage’ and ‘Cuvees de Prestige’, the liqueur d’expedition is prepared with the same wine as that disgorged. This is to ensure that the wines bouquet and character is not changed in any way. For non-vintage wines the dosage can use reserve wines from previous harvests.
Carbon dioxide can cause a reduction of one’s perception of sugar. Only the best Champagnes have the gentleness to be ‘perfectly balanced’ without any added sweetness. It can also be said that excessive sweetening conceals and helps to mask any defects in Champagne. Perhaps the best known natural (zero dosage) wine is the Piper Heidsieck Brut Sauvage. Dosage also allows for minor attenuations of a Champagne / sparkling wines character. The addition of a recent vintage as part of the dosage can add freshness and brighten up the finished blend.
The amount of dosage given to each wine varies typically from 0-45ml. The remaining amount of liquid to finish with 750ml comes from sparkling wine added before the cork and muselet are added. The dosage and added sparkling wine have to at the same temperature of the bottled wines. Following dosage, cork and muselet the bottles are then shaken to distribute the dosage within the wine and rest for up to 6 months before dressing (labelling) and selling.