Refermenting bottled wine is a typical procedure of the classic method of producing sparkling wines. Bubbly wines are born from a second fermentation after that of the grape must fermentation.
The bottles are systematically placed horizontally in a wine cellar at controlled temperatures and are regularly rotated a quarter or an eighth while on an incline, so that the yeasts at the bottom of the bottles, make their way upwards towards the cork. This is the stage where wine is refermented.
The yeasts are brought to the top so they can actually be extracted from the bottle and then recorked, getting them ready to be sold to the public. This is where a few French terms come into play – liquer d’expedition, literally translated “syrup dosage”. This is not an easy process and in order to do it properly, ensuring that the yeast on the cork is gone, a traditional, well-established method is still employed – isolating the wine by the cork.
The neck of the bottle is frozen with a propylene glycol solution which is non-toxic, colorless and odorless. This isolates the wine by the cork, and when it is frozen, the bottle is opened and the frozen wine is immediately ejected due to pressure from the rest of the bottle. And with it, the unwanted yeast is ejected as well.
Ejecting the iced cap means, however, also removing a small amount of sparkling wine from the neck of the bottle. If the product was marketed as such, all the sparkling wines which have undergone the “classic method” of bottling would have a notable amount of liquid missing from the bottle. This is where the liqueur d’expedition comes in. This sugary liquid is added to the bottles in order to refill the missing liquid.
The expedition liqueur is only an expedient used to refill the sparkling bottles. The amount of liqueur d’expedition that can be used to fill each bottle, depends entirely on the denomination of the wine and the type of product it is. A sugar residue of less than three grams per liter of liquor will create a sparkling wine of Zero Dosage (Pas Dosè); less than six grams per liter will create an Extra Brut; less than or equal to 12 grams will create a Brut; and a residual sugar greater than 50 grams per liter will create a sweet sparkling wine.
The presence of liqueur inside the neck of the bottle is therefore indispensable to define the type of sparkling wine we will pour into our flute. Brut, Extra Brut, Dry, Extra Dry and so on are the kind of sparkling wines which adhere to the classico method. It would be unthinkable, not to mention useless, to add expedition liqueur to a sparkling wine that is made with the Charmat method.
