Cider apple
Cider is made in several countries and can be made from any apples. Historically the flavours preferred and varieties used to produce cider have varied by region. Many of the most traditional apple varieties used for ciders come from or are derived from those from Devon, Somerset and Herefordshire in England, Normandy in France, and Asturias in Spain, and these areas are considered to have their own broad cider styles although the many exceptions make this more of a historic footnote. Normandy cider is usually naturally carbonated and clear: Asturian cider apple varieties are mainly 'sharps' or mild 'bittersweets', producing a mildly acidic cider which is customarily served by being poured from height into the glass to oxygenate it.
Cider
Most of the natural sugar in apples are used up in the fermentation process and are converted into alcohol, and carbon dioxide. If the fermentation goes all the way, the cider will have no perceivable residual sugar and be dry. This means that the cider will not taste sweet, and might show more bitterness, or acidity. Ciders are made in many parts of Europe and in the United States and each country has different representations of cider with different flavour compounds. Keeving is a traditional method of fermentation with low amounts of nitrogen in French and English ciders that is intended to slow down the rate of fermentation in hopes of retaining high esters as well as retaining some residual sugar in the bottled cider to increase effervescence in the aging process. Ciders can be back sweetened, after fermentation is complete to add a sweet taste and balance out acids, tannins, and bitterness. Natural sugar can be used but this can restart fermentation in a bottle if not filtered correctly. Artificial sweeteners can be used which are non-fermentable but some of these create an aftertaste, such as saccharin or sucralose, yet some of these are known for adding off flavour compounds.