Journal | September 25, 2016
This time of year the first thing I do in the morning in check the weather forecast. Its the last thing I do before going to bed. I also check it during the day, at lunch and in the evening. I know exactly when certain radio stations broadcast weather reports. I have five bookmarked weather internet sites on my laptop. I’m not alone.This is a ritual of all winegrowers during harvest.
The reason is rain. Rain is a game changer So far we have been very lucky with only one small rain event during harvest. We still have two weeks to go and they are a very important two weeks for the red wines. Cabernet Sauvignon is our most prized red grape. It can produce classic Medocian styled wines when grown on the granite hillsides of the Blue Ridge. It is however a late ripening grape. Cabernet Sauvignon’s beauty is in its tannins which are in the skins and seeds. These tannins need to be ripe in order to produce world class wines. We are very close to getting to that point now, but need just a bit more time. The grapes are at their most fragile just before harvest. Ripe skins break easily and are very susceptible to rot. This is why we fret so much about rain.
A quick shower is no problem, but a prolonged, settled rain is. Cooler temperatures can mitigate rains effects on the grapes. So why exactly is rain such a problem? 1. Skin integrity. A long soaking rain, especially under warm conditions will swell the berries and expand the skins sometimes to the point of splitting (worst case scenario). The skins become so thin that they lose their protective quality and their tannin strength. “The fuse has been lit” as a Bordeaux friend remarked. Its just a mater of time before rot sets in. 2. Rot, specifically botrytis rot can explode under the right conditions. Within 24 hours the grapes can go from picture perfect to fuzzy grey blobs. Once this happens there is no possibility of making a great wine. The botrytis mold eats away the skin tannins, color and flavor. Thoughtful winemaking can cut loses and make a simple, light ‘Bistro’ wine. 3. Rain dilutes the juice. As rain water is absorbed by vine roots and skins, it swells the berries and dilutes all components of the juice and therefor, the resulting wine.
Not all rains are equal. A quick shower under cool conditions is a non-event. A prolonged, steady three day tropical blow can be a disaster. This is why the remnants of hurricanes can be a deal breaker.
The good new is that we have lots of ripe grapes ready to be picked. We start tomorrow in haste and will basically continue until there are no more grapes on the vines. This will take two weeks under normal circumstances, but if significant rain threatens, we could finish up much sooner. Better to have slightly under-ripe grapes than mush.