Back Wine made from grapes that have been dried (the bunches are left to dry on a bed of straw after harvesting) for around six weeks, then pressed. This process of over-ripening through water evaporation significantly increases the sugar content. The second unique feature is that fermentation stops naturally when the alcohol content reaches around 15%. A long ageing period, from 18 months in Hermitage to up to 3 years in the Jura, produces a naturally sweet, very rich wine with good ageing potential. It is served chilled at 8°C, as an aperitif or with sweet desserts. In Italy, the same process is used for a wine called passito. The yield of straw wines is one of the lowest. 100 kg of grapes produce only about 25 litres of wine. It is sold in half-bottles at a high price. The product is virtually eternal. See straw wine.