What makes cider, cider? Beyond fermentation it really comes down to the types of apples and yeast used to make the base juice. There is a misnomer that all apples are created equal and that idea is patently false. Much like varietals of grapes there are specific apples that have characteristics that drastically alter the style of cider you can create. Cider apples in particular are generally far too tannic and acidic to eat. There are four main classifications of cider apples:
Sweets This group low in acidity and low in tannins but high in sugar (great for producing alcohol).
Sharps are the group high in acidity but low in tannins. The most common acid in apples is malic acid and what many perceive as “tart”.
Bittersweets are the group low in acidity but high in tannins. Tannins are generally are perceived as bitter and a bit astringent.
Bittersharps are the group high in both acidity. The combination of tannins and acids are what most people describe as “bite” in a cider.
The prohibition in the United States drastically altered the amount of cider apples commercially available to people producing cider but that is a tale for another day.