Royalty In Rot: For wine grapes, a death deferred by a Noble fungus

Illustration by Joel Hedstrom

Winemakers spend lots of energy during the growing season battling pests and fending off vine diseases that seek to destroy grapes. But there’s one they actually welcome—the so-called “Noble Rot,” or as it is formally known, Botrytis cinerea.

Botrytis is a fungal disease that typically lays dormant in almost all vineyards at all times. It becomes activated and begins to germinate in humid weather, causing a gray rot to develop and destroy the fruit. So how does this rather disgusting disease get called “noble” like it’s all fancy and such? Because its presence can result in some of the most lauded dessert wines in the world.

In order for Noble Rot to be just that, a few things must happen. Botrytis must be present in the vineyard and get triggered by moisture in the air (usually during early morning) so it can feast on the poor unsuspecting white grapes. Then as the day goes on, the sun rises and the moisture evaporates, halting the feast and allowing the grapes to shrivel. This process carries on for several days, eventually leaving the vines with shrunken, ugly, brown grapes that carry very little juice and must be handpicked. But what juice is left is precious. 

The juice from afflicted grapes produces sweet, textured wines that have flavors and aromas of honeysuckle, candied ginger, apricots, and beeswax. They are often served as dessert wines in small amounts or alongside snappy, salty cheeses and charcuterie as a delectable and contrasting pairing. 

These wines come from grapes often grown near moving bodies of water that add to the misty, damp mornings necessary for Botrytis to thrive: chenin blanc in the Loire Valley; semillon or sauvignon blanc that make Sauternes wine near the Ciron and Garonne rivers; furmint and hárslevelü for the Hungarian Royal Tokaji wines from vineyards near the Bodrog and Tisza rivers; or all of the late-harvest German rieslings grown by the Moselle, Nahe, and Rhine rivers. The microclimate is incredibly important to Noble Rot—grapes like semillon are a perfect venue because of their thin skin, oily palate, and close-clustered bunches that retain moisture. 

Noble Rot produces wines that showcase grapes and regions in a new light for consumers. These wines don’t come around often and when they do they are precious and delicious. Next time you are in a bottle shop keep your eyes peeled for often smaller, 375-milliliter bottles of this golden honeyed treat. Or perhaps, at your next dinner out inquire about dessert wines from Botrytis-affected grapes that a restaurant is offering—and don’t be afraid to pair with something a little on the savory side.

Read more enlightening articles on the world of wine in our column, Wine Time.