After the sublime experience of imbibing De Bortoli’s Noble One Botrytised Semillon 2006 at our wine tasting dinner last week, I was keen to learn more about how these magical botrytised dessert wines, which had delighted Thomas Jefferson in the 18th century, are made.

Possibly one of the most intriguing aspects of botrytised wines are the grapes used in their production. They are infected by noble rot – a fungus that attacks the fruit, absorbing water and shriveling the skins. The grapes look bloody awful but the best give forth an amazing liquid that has been described as nectar for the gods!

The most acclaimed botrytised wines are the French Sauternes and in particular the ethereal wines of Chateau D’Yquem, the only Sauternes to be recognised as Premier Cru Grande Superieur (Great First Growth) in the Bordeaux Classification of 1855.

The climate of the tiny Sauternes appellation is the key ingredient: early-morning moisture late in the growing season engenders the development of mould on the grapes, activating dormant spores of Botrytis cinerea. Providing the mists evaporate each day, drying out the vines and their fruit, the mould will tend towards noble rot rather than the soddy grey rot, which happens if the weather stays too damp. The noble rot  desiccates the grapes one-by-one, concentrating the sugars as the water evaporates without developing any off-putting, mouldy flavours, and, in fact, contributing an appealing flavour all of its own.

The best Sauternes are generally made from two grape varieties: semillon,and sauvignon blanc.  At Chateau d’Yquem, the grapes are picked by hand at least six times during the harvest season to ensure that only the botrytised grapes are selected.

In general, great Sauternes are characterised by their complexity, balance, opulence, vibrancy and a relatively high acidity that helps to balance the … Read the rest