A Very Ancient Craft
This wine should contain carbon dioxide produced by a secondary fermentation in bottle. It should be moderately strong, 12% to 13% alcohol, and if possible should be served not quite dry, that is with a specific gravity of 1.000 to 1.002. When maturation is nearly complete and the wine is bottled it should be racked into proper thick champagne bottles capable of resisting a high gas pressure and you should never use ordinary wine bottles. These could be most dangerous if they were to explode. When the wine is bottled a good teaspoonful of sugar dissolved in some of the wine should be added to each bottle, together with a few drops of a fermenting champagne yeast. Good tight-fitting cork stoppers should be used, and these should be wired down. After three months a deposit will be seen in the bottles and if your facilities permit the bottles should be daily twisted and slowly inverted until they are upside down. Alternatively they can be slowly inverted in a cardboard wine case and each day twisted and slightly shaken so that the sediment gradually falls from the side of the, bottle until it is resting on the cork.
Many people now have deep-freeze facilities and it would be a convenience to make up a freezing mixture and stand the necks of the bottles in the mixture until the sediment is frozen on to the cork. By careful manipulation the wire should be cut, the cork and sediment removed and a teaspoonful of sugar syrup added in its place; the bottle should be re-corked and re-wired as quickly as possible.
If deep-freeze facilities are not available chill the bottles as hard as possible in an ordinary refrigerator, not forgetting to keep them upside down, then remove the bottles one by one, and whilst holding the bottle still upside down, cut the wire, pull out the cork, slip your thumb over the mouth of the bottle and bring it upright. With your other hand add the sugar syrup and a fresh cork--without spilling any of the wine ! This is clearly a very highly skilled task ! In the champagne cellars it is routine, but it can be done at home and has been done efficiently by many amateur winemakers. This extra trouble means that when you serve your sparkling wine you will have no trace of sediment to spoil the appearance of the wine as you pour it into glasses. Clearly, a cloudy wine would spoil. the entire effect of the sparkling bubbles of gas in an otherwise brilliantly clear wine.
Shortly after the removal of the lees of the bottle fermentation the wine may be used. It should be served cool, that is about 55"F., so that all the bubbles do not evanesce too quickly, but not so cool that they are inhibited.