Cider
Cider ( ) is an alcoholic beverage made from the fermented juice of apples. Cider is popular in the United Kingdom, especially in the West Country, and widely available. The UK has the world's highest per capita consumption, as well as its largest cider-producing companies. Cider is also popular in many Commonwealth countries, such as India, Canada, Australia, and New Zealand. Aside from the UK and its former colonies, cider is popular in other European countries including Ireland, Portugal (mainly in Minho and Madeira), France (particularly Brittany and Normandy), northern Italy (Piedmont and Friuli), and Spain (especially Asturias and the Basque Country). Central Europe also has its own types of cider with Rhineland-Palatinate and Hesse producing a particularly tart version known as Apfelwein. In the U.S. and parts of Canada, varieties of fermented cider are often called "hard cider" to distinguish alcoholic cider from non-alcoholic "cider" or "sweet cider", also made from apples.
Cider
Fermentation of ciders occurs by a very similar mechanism to the fermentation of wine. The process of alcoholic fermentation is characterized by the conversion of simple sugars into ethanol by yeasts, especially "Saccharomyces cerevisiae". This is because, as “Crabtree positive” yeasts, they produce ethanol even during aerobic fermentation; in contrast, Crabtree-negative yeasts produce only biomass and carbon dioxide. This adaptation allows them a competitive edge in the fermentation of ciders due to their high alcohol tolerance, and because of this tolerance, it is common for ciders to be fermented to dryness, although that is not always the case. Fermentations will carry on until the yeasts run out of nutrients and can no longer metabolize, resulting in a "stuck" fermentation, or the fermentation is stopped.