sweet noble rot

How sweet it is to be back at home. After a long few weeks hopping about, it was great to come back to something familiar. As soon as I dropped my bags in the doorway, I went exploring for a post-travel snack in my nearly emptied refrigerator. Passing on stale pita and plain yogurt, I was excited to find a tupperware full of blueberries. On opening the lid, however, I was only fortunate enough to discover my free "gift-with-purchase" had blossomed - a nice, white fuzz coating my overly ripe snack.

Rotting, moldy things are typically to be avoided, e.g. berries, leftovers, roadkill. This got me thinking, however, as I turned to the next closest thing (my wine rack). Noble rot is key to the syrupy sweetness that makes the popular (and pricey) dessert wines of Sauternes and Hungary so prized. I really had no idea of how noble rot works or its role in the vinification process, so I took a break from tasting anything this weekend (thanks a lot, first cold of the season) and dug around in my wine encyclopedia. And online. After all, if it's on the internet, it must be true.

Officially known as botrytis cinerea, noble rot or pourriture noble, is a fungal growth that appears on grapes late in harvest season and increases the alcoholic potential while concentrating the sugary juice. Unlike the standard fuzzy stuff that grows on food, grape growers actually wait and hope and keep their fingers crossed that the stuff will show. As with other fungi, it usually appears later in the harvest season when there is some moisture in the air to provide a friendly growing environment. The climate around Sauternes is ideal for our friend botrytis, whose spores are also indigenous to the region - maybe why Sauternes is the source of such legendary wines.

What happens as the botrytis spores grow is key to the concentrated sweetness and high alcohol content that define these wines. The spores feed off of the grape's extra moisture, concentrating the remaining juice into a thick and sugary mix. Because botrytized grapes are typically harvested one-by-one, the making of wine from these harvests is highly labor intensive. Once the grapes are harvested and used to make wine, the sugar content promotes alcohol creation in the fermentation process. The results are the heavenly (yes, really) Sauternes and aszu wines, as well as some lesser known German and Italian styles.

I won't get into detail on these wines now, but I do suddenly have a craving for a glass and some accompanying dessert...

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Tasted: Chateau Rieussec
To Taste: Chateau d'Yquem (should you be so lucky)

How Noble Rot Produces Sweet Wine
Sauternes Vintage Chart
Profile on Chateau d'Yquem
Hungary Returns to a Sweet Past

photo: Hans Voorn via flickr