Noble Rot

A fungus with two faces.

Botrytis cinerea is the name of the fungus which is responsable for noblerot, as well as greyrot, on the grapes. It nests on the skin and produces enzymes that affect its structure. That is why it can inject its mycelium into the berry and, in this way, extract certain substances (ex. sugars) and change some others (ex. certain acids). The weakening of the skin increases the evaporation of the juice, and therefore also the concentration of the different taste elements in it (ex. sugars, but more important still, acids, bitters, minerals...). After a very selective picking, an extremely rich juice is produced which is the basis of some of the most complex wines in the world. In this case we are of course in the presence of noblerot or "pourriture noble". But it can easily be otherwise : not very much is needed for the fungus to develop greyrot, which results in the complete loss of the harvest.

A very special variety in a unique microclimate.

To limit the risk of greyrot, it is of the utmost importance to recognize and to stimulate the ideal circumstances for the development of noblerot. We do know that the fungus needs humidity to prosper, so the proximity of a river, which can produce de necessary morning mist, is of great importance. But once the fungus has done its work, we need sun and wind to concentrate the juice. This requires a very specific microclimate, but also certain grape varieties and adapted cultural methods. As there may occur, even in merely dry regions, some longer rainperiods, mainly rustic varieties will be recommended (chenin, riesling, semillon, furmint...). A low yield will also be needed, as small, scattered grapes will develop noblerot more easily, whereas larger ones, growing close together, will be a lot more susceptible to greyrot.   And finaly, only a very severe picking, in several selective passages, can garantee a pure harvest. Then, as noble and greyrot often develop together on the same vines, all the berries infested by greyrot must be eliminated from the grapes. At Juchepie this means that we do 4 to 8 passages through the vineyard, over a period of 6 to 8 weeks.