Champagne when it is made has its second fermentation in the bottle: this is to put the bubbles in. At the end of this fermentation the wine is bone dry. There is no sugar left in it. When the wine is being got ready for sale, the cork is carefully removed and sweetening added. While for dry champagne little is put in, for medium sweet champagne more is added. Imperial Russia used to be the market taking the highest 'dosage'.