What Is Noble Rot?
If climate conditions in autumn are warm and very humid, grapes left on the vine may be infected by a fungus called botrytis cinerea or noble rot. Botrytized grapes are shrivelled and dehydrated, but the sweetness is concentrated. Some grape varieties are affected more than others, namely Riesling, Sauvignon Blanc, Chenin Blanc, Semillon and Gewürztraminer. An excellent example of a very sweet dessert wine made from these grapes is Nederburg’s famous Edelkeur.