How Fungus Yields Sweet Nectar
Harvest is here. It’s our busiest time of the growing season. The weather has really thrown many growers for a loop and now that fruit is being picked, the order the grapes are coming in is, well… different. For example, this week, we’re picking Viognier, Zinfandel (Famighetti Vineyard) and Sauvignon Blanc (Bavarian Lion). We picked Chardonnay last week. Normally, Sauvignon Blanc would be the first varietal to hit our winery.
It so happens that there is a chance of rain late this week just as grapes are scheduled to be picked, and this is coming right on the heels of a big weekend heat wave. How does all of this affect the grapes on the vine?
Heat can certainly spike sugar ripeness and this can impact the picking schedule. Moist conditions can give way to powdery mildew and this is definitely a concern now, as it has been most of the growing season. But there is a silver lining.
When moist conditions are followed by warmer weather, humidity and wind, something very magical happens. Botrytis cinerea, commonly referred to as “noble rot” is extremely beneficial to the taste of the wine in your glass. How?
Botrytis extracts water without changing the grapes’ acid to sugar ratio. As a matter of fact, this is the only way grapes can intensify their juice to create the sweet nectar that’s known as a dessert wine, like our late harvest Semillon, which is nicely resting in barrels. French Sauternes like Chateau Yquem which might be the best known, is essential Botrytis-affected Semillon, just like our sweet nectar.