Sorting Table Part 2 and a Bit of Chemistry

A large group showed up last Saturday at Vint Hill Craft Winery to sort the Cabernet Sauvignon that had earlier arrived from Arciero Vineyards in Paso Robles, California. Rather than dumping the grapes into a hopper, DJ put the box of grapes onto the end of the first sorting table and cut out an area of the box. Just as two weeks ago, people on the first sorting table removed stems, vines, leaves and grapes with a fungus on them. The grapes than proceed onto an elevator to the destemmer. From the destemmer the grapes passed along a second sorting table. At the end of the second sorting table the grapes were gently crushed using an empty bucket. The crushed grapes fell into a fermentation bin.

The grapes and juice in this bin were gently stirred. Three substances were added to the fermentation bin. Each of these helps with color stability. The Lafase He Grand Cru, an enzyme, was dissolved in water and added to the must. This enzyme helps to extract gentle tannins. The second liquid added to the fermentation bin was Color Pro. Color Pro is a pectinase that helps break down the cell walls of red grapes and gently extract phenols and tannins. Wines made with this pectinase tend to have increased tannins, reduced herbaceous character and improved clarity. The last item added to the fermentation bin was brownish-red powder, VR Supra. This fermentation tannin helps to keep indigenous tannins in the must rather than those tannins precipitating out. It will also help improve the mid-palate mouthfeel.

Finally I collected some juice to gather some lab data. First I placed some of the juice on a refractrometer and get the brix level. The Cabernet Sauvignon measured 23.9 brix. That level of brix has the potential of making a wine that is about 13.2 percent alcohol. Next I used a machine to calculate the pH and TA. The Cabernet Sauvignon measured a pH of 3.94. This was a bit high. It would be better to have it around 3.6. In order to lower the pH, acid will need to be added to the fermentation bins. The TA measured 4.57. That was low. One would hope for a TA around 7.0. Adding the acid to the fermentation bin should increase the TA level.

You get the hang of things after doing several samples. So the chemistry isn’t that hard. It’s knowing what to do with the data that is important though.

View a one-minute slide show about sorting tables and chemistry.


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