The grapes are pressed very gently and varieties are vinified separately off the skins to produce a low alcohol Brut white wine which is racked and allowed to mature in tank until the spring. The lots are then blended together, using some Reserve wines from earlier fine vintages. The resulting wine is then bottled with special "flocculent" yeasts and sugars and is refermented under a crown cork. There follows a period of ageing, when the yeasts flavour the wine and give it characteristic brioche aromas. Gobillard then opens the bottles ("de-gorgement"), removing the yeast in the process, adds a dosage of grape sugars, inserts the characteristic mushroom cork, and ships the wine.