Have you ever seen a Botrytis cinerea infected bunch of grapes? If you have you will never forget it. And if you have ever helped harvest some you will really never forget it! It is disgusting looking. Like something you would find in the garbage after weeks of it being left out. But it is desired for some wineries, and it is undesired by others. I loved it when Pierre Lurton, director of Château Cheval-Blanc and CEO of Château d’Yquem, said the above quote in a staff training, because considering his situation, it really rings true that fungus can be disaster, or it can be a great gift.
Botrytis cinerea (or called Botrytis for the rest of this post) can take the form of noble rot or take the form of grey rot. Grey rot develops when there are damaged, split grapes and the fungus finds its way into the pulp and makes the berries become rotten. It travels from vine to vine by running or dripping water, and hence, thrives in rainy, damp conditions. It takes the form of noble rot by the fungus attacking ripe, undamaged white grapes and under certain circumstances can create some of the greatest sweet wines in the world. The conditions that help to encourage noble rot are a moderate climate in which the humidity during the Summer creates an early morning mists that helps to develop the fungus, and then with a warm, sunny Autumn in which the grapes are dried and the fungus is restrained. Sauternes and Tokaj are the classic regions that have these ideal conditions for most vintages.
As I said before, Botrytis likes wet conditions, and hence it can be disaster in very wet vintages in the form of grey rot, especially if it rains before harvest. In 1991, Cheval-Blanc did not make a grand vin. It was 100% declassified. This was due to the large amounts of rain right before harvest. Grey rot was out of control that year, and particularly damaging to Pomerol and Saint-Émilion estates since Merlot is a variety highly susceptible to botrytis.
Also, grey rot is a secondary invader that infects damaged grapes. Machinery, hail, insects or birds can cause major problems by splitting the grapes and leaving the pulp exposed to be infected by Botrytis. Bedell Cellars in Long Island, New York, said that the biggest issue they need to combat in the vineyard is the birds. I visited them a couple months back and I saw netting to protect the vines from the birds, and they use two nets for each Syrah vine… Who knew New York birds liked Syrah so much?! The birds will split the grapes and then grey rot will take over. This could devastate their vineyards considering that this area typically receives a lot of rain and humidity.
Grape varieties that are the most susceptible to botrytis are thin-skinned varieties with tight clusters. If botrytis is not wanted in an area where it is prevalent then varieties with smaller leaves that are less vigorous that have looser bunches and thicker skins are more ideal. But if the goal of the grape grower is noble rot then thin-skinned varieties such as Sémillon, Riesling, Chenin Blanc and Furmint are a great choice. Besides Sémillon having its classic home in Sauternes, there are some that would argue that it also has a newly made classic home in Hunter Valley, Australia.
When is Botrytis desirable?
Margan winery in Hunter Valley has a perfect breeding ground for Botrytis with its elevated humidity. Their botrytized Sémillon is made in the style of a French Sauternes. When botrytis penetrates the skins of their whole, ripe Sémillon it dehydrates the grapes while maintaining the sugar level so the juice ends up having higher sugar content. Also, it adds aromatic complexity with honey, marmalade and musk notes. I know musk sounds like a weird thing to get from a wine… but there is sometimes a savory note in a botrytized wine, which is great for balancing all that sweetness, and so musk or mushroom are terms that are typically used for those savory notes.
When is Botrytis undesirable?
Botrytis, whether in noble rot or grey rot form, is always bad for yields and requires a lot of manual labor, and manual labor that knows what they are doing trying to sort through the dark, shriveled, gooey bunches. Château d’Yquem employs 140 skilled pickers during harvest and they will go through the vineyards 5 or 6 times for up to 3 months sometimes. And one vine makes the equivalent of only one glass of wine!
Also, Botrytis may increase the chances for volatile acidity and off flavors. Hambledon Vineyards in Hampshire, England will leave their Chardonnay out a week longer than their Pinot Noir or Pinot Meunier to add more richness and body for their sparkling wines. But they have had undesirable botrytis adding an unwelcomed honey or marmalade taste that would be unacceptable for their intended fresh style of sparkling wine.
As mentioned before, Botrytis was a disaster for Cheval-Blanc in certain vintages. Since red wine includes maceration on the skins it can become a more serious problem then white wines, especially those that do not employ skin contact. Loss of pigment is an issue in this case, but the significant amounts of off-flavors becomes the biggest issue to tackle in a red wine. Charcoal fining is usually the only way to get rid of taint in a Botrytis affected red wine, but that is not an option for fine wine quality.
There is the simple idea that a producer finds Botrytis undesirable if they do not want to produce a sweet wine. And finally the potential alcohol may not be allowed in some local appellation laws.
It is interesting that a fungus could ever be considered as desirable. It is one of those examples of how something that has a long list of negatives that under the right conditions can create something so special that it makes all the undesirable factors worth all the trouble. I like to think how this relates to me taking something on like the MW program. And perhaps you have something in your life where you feel the same. Yes, when I talk about the long list of undesirable things about the program it becomes a mystery to many others of why I would attempt it. Well, I guess I am expecting that something special within me is waiting to emerge when forced under these extreme conditions. And then I think about what those people said right before they tried the first noble rot infected grapes, “You never know unless you try.”
***This is my last blog post until mid-January due to hectic holiday schedule and preparing for mock MW exams in early January.
Tasting note of Cheval Blanc vertical on October 16th, 2014
-2000 Cheval Blanc:
2000 Cheval Blanc with a blend of almost 50:50 Merlot & Cabernet Franc, even though some reports say 53:47 dominate Merlot (not all Cheval Blanc wines are a blend that dominates with Cabernet Franc). This vintage is sexy (yes, I used the “sexy” word)…. but in my defense it is sexy. Lush tannins that seem to melt into the wine and explosion of blueberry and cassis with tarragon, smoked meats, and bark. Even though it is such a pleasure now I have a feeling it has a lot more to give.
-2003 Cheval Blanc:
Actually not a bad 2003…the winemaker said they really went out of their way to keep this vintage fresh. Beautiful perfumed notes with spicy exotic notes. Only bright pristine fruit, no raisin notes. I think that the idea that Cheval Blanc grows a larger % of Cabernet Franc than Merlot is helpful for hot vintages.
-2005 Cheval Blanc:
A richer body Cheval Blanc than normal but still with the classic dried leaves character I get from Cheval Blanc. More black fruit than red or purple and a dusty earth instead of wet earth which means for me they are lighter notes that roll around my head. Stunning.
-2006 Cheval Blanc:
Much more linear in body than 2003 and 2005 but a lot more tannic structure. Pure black fruit and mint. The long length and great fresh acidity suggests this may be a classic beauty with some time.. but it was very tight at the time I tasted it.
Tasting note of 1975 d’Yquem on May 14th, 2014
1975 was a difficult vintage for Bordeaux, but turned out to produce some of the best Sauternes in modern times. And 1975 d’Yquem is legendary. I must admit I am not a huge sweet wine drinker.. I actually don’t like sweets at all. And I’m not trying to seem cool turning my nose at anything with sweetness. I have always been this way, even as a kid. But I do love old sweet wines. The combination of mature notes with the sweet palate is really interesting to me. This ’75 still seemed so young. Nice racy acidity, especially for Sauternes. Yes, it had fig, quince, marmalade… but also a great smoky minerality… and the extraordinarily long length finishes with hints of grilled pineapples. It seems that it has still a couple more decades to go.