Noble Rot: The Fungus That Makes Yummy, Sweet Wine

Noble Rot Semillon grapes in Sauternes

What is Noble Rot?

Usually the thought of rotten anything would churn one’s stomach. But is there such a thing as “good rot?” Noble Rot is a Grey Mold caused by Botrytis fungi that attack healthy, ripe grapes and cause them to turn exceptionally sweet. Although a fungal attack on grapes is usually considered a threat and possible disaster for most wine styles, there are vineyards that purposely allow the grapes to rot this way in order to make a very sweet dessert wine.

Noble Rot takes place in some regions that have high levels of humidity and mist in the mornings, followed by sunny and dry afternoons around the time of grape harvest. These damp conditions lead to rot developing on the grape skins. The fungus pierces tiny holes in the grapes, causing the water to evaporate and grapes to shrivel. With low levels of water, the grapes now have extremely concentrated flavors and high sugar. These grape are then harvested and made into wine.

Noble Rot Riesling Grapes, Germany

Because the grape juice is so sweet, the yeast cannot convert all the sugar into alcohol. The end product is a very sweet wine. These wines are often aged in oak barrels where they pick up additional flavors of vanilla and other sweet spices.

Wines made from Noble Rot grapes are expensive due to the amount of labor and care required to harvest and process them. In addition, some vintages (years) struggle to make large volumes of Noble Rot grapes due to less humidity and dryer air. The rarity and small volumes add to the final price of the wine. Grapes that make the best Noble Rot wines are Semillon, Sauvignon Blanc, Chenin Blanc, Riesling, Gewürztraminer, and Muscat.

Where is Noble Rot?

In Sauternes, Bordeaux, Semillon grapes infected with Noble Rot are blended with Sauvignon Blanc and Muscadelle to make a delicious wine with aromas of apricot and citrus peel. Noble Rot is also used to produce Tokaj Szamorodni in Hungary, and Beerenauslesen and Trockenbeerenauslesen in Germany and Austria.

Final Taste

When the fungus pokes holes in the grapes around harvest time, the grapes become very sweet and flavorful due to their water loss. In addition to a grape’s natural fruit aromas, the rot leaves new concentrated flavors of honeysuckle, dried apricots, beeswax, and honey. Once aged in oak, the wine can also produce secondary and tertiary flavors of toast, nuts, caramel, butterscotch, vanilla, and ginger.

Food Pairings

This dessert wine is often paired with sweet or spicy dishes. Its most famous French pairing is Foie Gras made of fatty duck liver served with jam, figs, or dates. They are also enjoyed along spicy Thai noodle dishes, hot curry entrees or flavorful roasted chicken. Dessert wines also compliment light sides such as strawberries & cream, fruit tarts, and blue cheese.


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4 thoughts on “Noble Rot: The Fungus That Makes Yummy, Sweet Wine

  1. Since I don’t care for sweet wines I’d probably pass on Nobel Rot, even though the pairings look interesting. But the pictures! It’s hard to believe it becomes a sought after wine

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