Noble Rot

Noble rot (Botrytis cinerea) is a fungus that has a significant impact on winemaking. Botrytis cinerea is known by two different names depending on its effect: noble rot and gray rot.

Noble Rot
Under ideal conditions, when humid and foggy mornings alternate with dry and sunny afternoons, Botrytis cinerea causes a positive process called botrytization. This process is crucial for producing high-quality sweet dessert wines, such as: Sauternes in France, Tokaji Aszú in Hungary, and Beerenauslese with Trockenbeerenauslese in Germany and Austria.

Noble rot causes grapes to lose water, concentrating sugars, acids, and aromas. The resulting wine is characterized by rich sweetness, complex aroma, and balanced acidity.

Gray Rot
In unfavorable conditions, especially during prolonged humidity and lack of sunshine, Botrytis cinerea causes a harmful infection known as gray rot. Gray rot can lead to grape rot, significantly reducing the quality and yield of the crop. In such cases, the mold attacks the grapes, causing them to soften, turn brown, and become inedible.

Botrytis cinerea is, therefore, a fungus with a dual character: it can be either harmful or extremely beneficial depending on the conditions in which it occurs. Its proper control and use are key to producing some of the best dessert wines in the world.

We write more about botrytized wine here.