Ripening of a grapevine

Evaluating the phenolic ripening of wine grapes is more important than just chemical analysis: Cantine Barbera experience

I'm walking with a very excited Pablo, my 3 year-old black hovawart, for our first official 2013 pre-harvest check, a significant as I am about to understand which is the ripening stage of the grapes and to make plans for the upcoming harvest.

Last week I did the same tour with my mom: she takes care of the vineyard during the winter, when I am busy with travels and tastings, winemaking and bottling, and is always very proud to pass me the baton at the end of veraison.
I am so happy with the great job she did this year: amazing sound grapes, a very important thing that should never be taken for granted, and balanced vineyards.
My first thought is that our timing is quite close to last vintage’s: maybe ripening is a bit slower this year, but everything may quickly change depending on temperatures.

I bring my refractometer just for doubt’s sake, but I will eventually pay more attention to what I see, feel and touch than to just the sugar level. Of course ripeness can be measured with specific chemical analysis, but I do believe that nothing is better than your senses to evaluate all physiological process in vines and grapes’ life.

The first grapes to get ripe is Chardonnay, so I will start from there.
First thing I do is to check the lignification of the stems as they turn from being flexible and green to hard and woody. Half an inch of wooden stem will mean a complete ripeness, and my grapes are on their way, as we can see from the picture.

Then it’s the turn of basal leaves, which start to wither as the ripening process goes on. This is a sign of water stress, which is daily routine here in Sicily, but it has to be managed very carefully: while a controlled water supply is very important to vines’ health in order to keep their balanced metabolic functions, excessive irrigation may lead to poor grapes’ quality.
My choice for this year will probably be for short cycles of night-time watering using a drip irrigation system before the vines become sensitive to major water deprivation, so that they will have time to metabolize humidity and stay away from ripening blockings. 

I finally taste a berry: its skin is already soft and elastic. It’s delicious and almost sweet, with a perceptible acidity. Confirming my feelings, the refractometer says 14 to 15 Babo degrees, with some peaks around 18 in the outer clusters. The seed is brown and already crunchy, but not very dark.

A week, maybe ten days, and we’ll be ready for harvest.

Lignificazione del tralcio

Appassimento delle foglie basali

Acini e vinaccioli quasi maturi