AN AMAZING FUNGUS
Semi-sweet and sweet wines are made around the world from a number of grape varieties grown in different ways on a wide
range of terroirsl. The grapes are picked and fermented in many diverse ways as well..
However, very few sweet wines are made with grapes affected by Botrytis cinerea, the microscopic fungus which is normally
a scourge, but can be transformed into "noble rot" under certain conditions.
A special set of circumstances calling for alternating wet (during which botrytis proliferates) and dry periods (which
concentrates the juice by removing water) are required for Botrytis cinerea to turn into noble rot. In effect, the fungus lives
on water and certain nutrients in grapes.
The grape skin shrivels, while the sugar and acid levels increase. Concentration thanks to Botrytis cinerea also adds much more
aromatic complexity than simply ripening in the sun as with raisined or late harvest wines.
The following regions are among the most famous for their sweet late-harvest white wines: Alsce, the Loire Valley, Germany and
Austria (Trockenbeerenauslese), and Hungary (Tokaj).