See also Cider on Wikipedia, and the disclaimer.

Cider is the fermented juice of apples. Usually, apples that are sour in taste are used, and late apples make better cider than early ones. The apples after gathering are left to mellow for some days. The juice is crushed out by passing the apples between fluted rollers or in mills of various kinds. The pulp is placed in bags or in wicker-work frames with holes, and the juice is drained into tubs. This juice is kept for the finest quality of cider. The rest is squeezed out in a press. This pressure, especially where unduly great, adds juice from the pipe and skins and gives it a coarser flavor, though in larger quantity. Eight to ten days' fermentation takes place in casks with large bungholes, the vinegary yeast frothing to the top, which is constantly removed. The cider is next freed of the sediment by being placed in fresh casks, and this is repeated in the spring. Champagne cider is made by bottling the juice before it is fully fermented. Cider contains from four to ten per cent. of alcohol.