There's a fungus among us.

Harvest 2011...hmmph! Even the large, commercial wineries in the Napa Valley are having a bit of a struggle with mould this vintage. Cabernet sauvignon is quite susceptible to quite a few fungi most notably Botrytis cinerea however, the fruit in the above photograph is showing a rather vigorous crop of penicillium. Scary, they're large enough to cast their own shadows.

Fungi lack chlorophyll and need to live on other organisms to obtain nourishment, they are parasitic. Fungal diseases are known as 'secondary invaders' because they thrive on grapes that have been damaged by birds and bees, or grapes that have already had their overall health compromised by diseases such as powdery mildew (Uncinula necator). Wet weather, in the run up to harvest, often causes the worst cases of infection on already injured grapes, so because of the early fall rains 2011 may be a bumper year for fungi.

Of course yeast is a type of fungus, but it's also very important for fermentation. Wine made from spoiled berries is often tainted with smells and tastes like, well, mould. Lovely. But, it is problematic vintages like 2011 that seperate the winemaking men from the boys. Ferment on...

Photograph courtesy of the Marketing Queen.