The first taste which people recognise and the first they notice is sweetness, which is registered on the tip of the tongue, almost like a tiny electric shock. The sugar content of a wine is usually given in grammes/litre. In sweet wines (for some the level has to be shown on the label) this may reach up to 60g/l, while in dry wines the residue is usually lower at 1-2g/l (up to 4 g/l is admissible). Depending on the quantity it is classified as medium dry ('abboccato') (up to 15 g/l), medium sweet ('amabile') (from 16-45 g/l), sweet or fortified and liqueur wines (over 45 g/l).
The ethyl alcohol (produced by the fermentation and considered as a sugary substance) also influences the sweetness of a wine. It is particularly responsible for the smoothness as it balances and dampens down the effects of acidity, thereby harmonising the balance of tastes.