Noble Rot Such a great name for a fungus, huh? Noble is defined as being ‘impressive in appearance,’ which would explain this perfectly. It’s impressively disgusting to look at in fact. So disgusting that grapes that are affected by noble rot in regions that are not familiar with it will discard it. Imagine if the folks in Tokaji did that, oh, my heart! I think a single tear just ran down my face. Ok ok, enough drama, let me explain what all this is about.
Noble Rot is caused by a fungus named Botrytis cinerea, often abbreviated as botrytis. Of all the different fungal diseases out there, this one has the greatest potential effect on wine quality, whether good or bad. When it’s bad, viticulturists can literally watch their crop rot right in front of them. If the botrytis affects unripe, damaged berries, it will turn to Grey Rot, the evil form of this. Grey rot will form in wet and humid climates, especially when there’s rainfall right around harvest time. Grey Rot also affects red skinned grapes – it will affect the pigment, turning the wine a grey-ish (off-black if you will) tint with foul odors of rot coming through. Really appealing, I know.
However, when the conditions are right, and the right grapes are affected, Noble Rot will prevail. What are the conditions you ask? Ah, great question. First of all, any light-skinned grape can work, but traditionally Semillon, Sauvignon Blanc, Chenin Blanc, Riesling, Gewurztraminer and Furmint are used and are particularly sensitive to botrytis. Second, the grapes also have to be ripe and undamaged. The last is that the weather conditions must be just right. This is super important and also super difficult to control, seeing as weather is a tricky little bitch. A temperate climate with humidity in the early morning mists, followed by warm, sunny afternoons that dry the grapes out is almost always necessary. This will allow the development of the fungus in the morning, but restrain it from spreading everywhere. Now comes another tricky part. The botrytis fungus does not spread evenly – usually. It can spread from grape to grape in different parts of the vineyard at different times, which is why harvesting will take several passages, or attempts at picking single grapes. The infected bunches, or parts of them, are picked just at the right infection levels while the grapes affected with grey rot are discarded. As you can see, it’s pretty labor intensive and is one of the factors of the scarcity and high price of these wines.
So now that we have harvested these gross, almost brown raisin-y looking grapes, you may be wondering how in the world these come to make such wonderfully golden hued, silky textured, delicious wines. It’s pretty interesting because it’s not that this fungus just dessicated and dehydrates the grapes of water, but leaves all the sugars intact and extra concentrated, it actually changes the chemical composition of the grape. We could go on and list everything it does, but it gets a little dry…notice the pun, so I’ll just leave it at it changes/forms various chemical compounds resulting in botrytized grape juice that is very different then regular grape juice. Fermentation of this grape juice can also be different because it can last way longer. In fact, it can last years! Of course, this can lead to a second fermentation, so care must be taken that this does not happen. Once safely in the bottle, assuming that everything has gone correctly, these wines can be aged for an extremely long time – we’re talking decades here, not just a few years. So cool.
Now that we have procurred a rare and precious bottle of the wine, perfectly aged and ready to go, what can you expect from the glass? Well, pure delight, of course! Actually, often botrytisied wines can be described as having a honeyed, nutty character to them, but botrytis is very distinct and once you smell it, you’ll understand. The regions most famous for these wines include Sauternes, France; Tokaji , Hungary; and Germany (usually labelled Beerenauslese or Trockenbeerenauslese). Feel free to stop by and check out the selection we have – anywhere from some nice Tokaji, to a German Chardonnay Trockenbeerenauslaese to Barsac, Sauternes. Be sure to keep your eyes open for all those people that are experimenting with botrytizied grapes too! In fact, we have a great example of a California wine made with partially botrysied grapes – the 2005 Austin Hope Roussanne. Stone fruit and honey flavors cover your tongue with golden flavors, and as you swallow, zippy minerality gives this off-dry wine a nicely balanced structure and leaves you yearning for the next sip. Yummm.