Early last week I walked through the vineyards in Westport and Dartmouth to evaluate the effect of a total of 5 inches of rain in the previous four days. Yes, 5 inches... almost as much rain in four days as we got the entire 2007 growing season. The crop isn't completely lost, and in fact some varietals are doing quite well (Merlot, Cabernet Franc), but it isn't pretty for some of the vineyard blocks. What are the major impacts of rain during harvest?
Dilution of flavor and sugar in the berries
The vines absorb more water than we would like them to at this stage and the result is that the intensity of flavors is reduced. Flavor intensity is one of the most important factors in producing good wines. Sugar is also diluted but that’s not as critical as the loss of flavor since sugar can be added to the juice prior to or during fermentation - a process called Chaptalization. This correction of the sugar amount in grape juice is usually allowed in cold climate regions like ours where sugar in the grapes may not naturally reach the desired level for good wines to be made. The French, especially in Burgundy, have been adding sugar to their grape juice for centuries.
The development of rot... Rot = Evil
I could leave it at that, but let me take it a little further. Wet grape clusters tend to rot especially on tightly closed clusters as in most Pinot varietals. Rot, even of the noble kind, does not add pleasant flavor to dry wines. Moreover, berries can burst if they swell beyond the skin's ability to retain all the water which is absorbed. With the "meat" of the berry exposed to insects and bacteria... it's a disaster in the making.
So, what's a winemaker to do?
Option 1: Pick early. Yes, sometimes a winemaker and vineyard manager will decide to just go ahead and harvest the grapes the day before the heavy rain. The problem with this is that sometimes the grapes aren't ripe enough to make good wine. It's a "play it safe" approach based on the idea that it is better to make some wine than no wine at all.
Option 2: If the decision is made to weather the storm and wait for full ripeness despite all the rain, then extra work has to be done at the winery. If quality wine is the goal.... the winery has to be very selective when the grapes are finally harvested. By this I mean that every berry that has developed rot should NOT be included in the making of the wine. This requires hand picking and hand sorting, a time and money consuming procedure. Even with the rotten berries removed, we still have to deal with the issue of lack of flavor intensity. Techniques like draining some of the grape juice from being in contact with the skins (called saigneé) or extending juice to skin contact can be used to try to make the best of it.
That's the price to pay for quality wine to be made in years when mother nature throws at us a pool of water just before harvest. This off course all comes with heavy financial implications tied to the loss of revenue from sales of either lesser quality wine, or in the worst case... no wine at all to be sold.
This my friends, is another reason why wine is such a special beverage unlike any other liquid we consume. Next time you fill the glass, think about it... not only is the wine you are drinking a reflection of its natural growing conditions during each individual year, there is no guarantee that the wine made from this vineyard and its vines will be there next year. This is why most wine labels include the year in which the grapes were grown - it's not just to make it fancy, the year (vintage) does really matter.
Nice writing. You are on my RSS reader now so I can read more from you down the road.
Posted by: jason kenny | January 16, 2009 at 05:13 AM