Cider is an alcoholic beverage made from the fermented juice of apples. The juice of most varieties of apple, including crab apples, can be used to make cider, but cider apples are best. The addition of sugar or extra fruit before a second fermentation increases the ethanol content of the resulting beverage. Cider alcohol content varies from 1.2% to 8.5% ABV (Alcohol by volume) or more in traditional English ciders, and 3.5% to 12% in continental ciders.

In UK law, it must contain at least 35% apple juice (fresh or from concentrate), although CAMRA (the Campaign for Real Ale) says that "real cider" must be at least 90% fresh apple juice. In the US, there is a 50% minimum. In France, cider must be made solely from apples.

The flavour of cider varies. Ciders can be classified from dry to sweet. Modern, mass-produced ciders closely resemble sparkling wine in appearance. When distilled, cider turns into fruit brandy.

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