Man or Bird? Who gets the grape?

Our Blog’s last vineyard update about fruit set and vine growth was a month ago, during the early stage of grape development.  While May and early June were marked by a heat wave, with the mercury hitting 40º, things have cooled down since mid June, and have stayed unusually temperate for Alentejan standards throughout this current period of veraison, which started the beginning of July.

Our early summer vineyard work, which consisted of both manual and machine work involving leaf removal and shoot trimming to expose the fruit to the morning sun and shade them from the hot afternoon sun, is now finished. The increased morning sun exposure helps increase the skin thickness and color, through a buildup of phenols and anthocyanins.

The women have now been sent home on their summer holidays, to rest before vintage starts in August.  For our white grape varieties, we are predicting an earlier than usual start of mid-August, and for the earliest red varieties, end-August as usual.  The only work left in the vineyard now is what Hans call ‘leaf maintenance’, ensuring through careful and minimal irrigation that the quality of the leaves stay green and healthy enough to allow them to keep on photosynthesizing, giving the grapes what they need to slowly ripen.

While a grape ripens, it gets softer, accumulates sugars, metabolizes and dilutes acids (tartaric and malic). In turn it becomes less bitter, intensifies in flavor, and for black grapes, become enriched in pigments.  The hotter the climate, the more efficiently the acids are metabolized. During ripening, bitterness, acidity, and vegetative characters (Methoxy pyrazine) diminish, while flavors and aroma compounds develop.

The ripening grapes are becoming more and more tantalizing to the birds,  who are getting increasingly difficult to chase away – bird scaring techniques is a whole other chapter of vineyard management, and keeps the grapegrower always on his toes trying to outwit the feathered invaders.