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
The acids in cider play a vital role in both the cider making process and in the final flavour of a finished cider. They are present in both apples and cider, and add a sour taste and a pungent odor to these respective substances. Acids also serve as a preservative in the cider since microbes grow less in lower pH environments and contribute to the fermentation process. Most ciders have a pH of between 3.3 and 4.1. The primary acid found in apples is malic acid which accounts for around 90% of the acid content in apples. Malic acid contributes to the tart and sour flavours found in cider, and typically between 4.5 and 7.5 grams of malic acid per liter of cider is preferred. Malic acid is also used to determine apple ripeness for harvesting, as its concentration decreases as the fruit ripens. Lactic acid is also commonly found in cider, and it is mainly formed from malo-lactic fermentation, a process that converts malic acid into lactic acid. This process rounds out the flavour of the cider while reducing a lot of the acidity and producing carbon dioxide as well. Other acids such as citric acid can be used to add taste after fermentation, but these acids are not typically found in high concentration in apples naturally.