After this second fermentation the wine is allowed to lie while the spent yeast settles as a sediment known as the lees. The bottle is turned on its head so that the yeast can fall into the neck and be removed. The turning is done gradually however, in a special rack, and over a number of days. The yeast is removed by freezing the bottle neck, uncapping the cork and letting the frozen plug pop out. A little bit of sweetened wine is added to top up the contents. Removing the yeast, topping up and re-corking the bottle is done very quickly so that not too much gas escapes. Then the proper champagne-type cork is fitted and wired in place to withstand the pressure in the bottle.
This lengthy and labour-intensive method of producing sparkling wine is known as the Champagne Method and in South Africa it is called Methode Cap Classique or MCC.
Sparkling wine can also be made by doing the secondary fermentation in a sealed tank and then bottling the wine under pressure of the gas which is already in the tank. This is the charmat method and produces a less expensive bubbly.
Finally, there’s the simplest method of all, which is to pump carbon dioxide into still wine at bottling time.
This injection method is used for most of the cheap and cheerful bubblies popped at weddings and birthdays.