Fermentation
Fermentation is best effected at a temperature of 40 to 60 degrees Fahrenheit. This is low for most kinds of fermentation, but works for cider as it leads to slower fermentation with less loss of delicate aromas.
Shortly before the fermentation consumes all the sugar, the liquor is "racked" into new vats. This leaves dead yeast cells and other undesirable material at the bottom of the old vat. At this point it becomes important to exclude airborne acetic bacteria, so care is taken to fill the vat completely, and the fermenting of the remaining available sugar generates a small amount of carbon dioxide that helps to prevent air seeping in. This also creates a certain amount of sparkle, and sometimes extra sugar is added at this stage for this purpose and also to raise the alcohol level. Racking is sometimes repeated if the liquor remains cloudy.
The cider is ready to drink at this point, though more often it is matured in the vats for up to two or three years.
Blending and Bottling
For larger-scale cider production, ciders from vats produced from different varieties of apple may be blended to accord with market taste. If the cider is to be bottled, usually some extra sugar is added for sparkle. Higher quality ciders can be made using the champagne method, but this is expensive in time and money and requires special corks, bottles, and other equipment.
References
- Household Cyclopedia, 1881
- Farmhouse Cider & Scrumpy, Bob Bunker 1999