It's that time of the season when the grapes begin to change color and the skins tend to soften some. With soft skins the grapes can expand and the clusters begin to tighten up. Only now can the sugars start to accumulate until you get the Brix reading you're looking for.
But it also is a sensitive time within the growing season when everything can go wrong too.
I remember when we had our first batch of grapes in Block One, and, though we were aware of the "bird issue", we didn't put a great deal of concern on the damage they could cause. Little did we know that birds are keenly aware of the sugar content of the grapes. Before we could pick the whites, the grackles flew in one night and completely cleaned us out. Anticipating a repeat, we watched the sugar level within the reds, and decided to pick these early. So did the birds. Again they came in at night and ate every grape hanging on the vines. Only skeletons were left. Since then we have been using Bird Gard, an automated sound system that screams out Red Tailed Hawk sounds along with distressed bird calls. We have had great success with it.
Late summer and fall tend to bring on the rains, and be a time when tropical storms and hurricanes race up the east coast dumping buckets of rain on our otherwise well cared for grapes. The vines tend to soak up this rain and send it straight up to the grapes. Where once you had a 16% sugar and climbing, following a rain it might drop down to 13 or 14% as the sugar levels get diluted. Two to three points may mean an additional week the grapes have to hang on the vine to regain these losses.
And with summer heat and rain comes humidity. All those latent fungus spores are rejuvenated and can't wait to get growing again. If there has been any skin rupture from the grapes expanding and cracking the skins, that means there is plenty of sugary food for them to have a population explosion. It'll make the bunch of grapes it is growing on no good, and possibly cause it to spread throughout the entire vineyard. It doesn't take long.
So we walk the rows, tasting samples of the grapes to see if they turn from tart to sweet. It is amazing how variety makes such as big difference. One chews a red grape, a Cabernet Franc for example, and you wince at its "sugar-free" pulp. Spitting out the seeds is a reflex action; these are not seedless Concords. From here you move over just one row, where the Seyval Blanc are; a greenish-yellow hybrid grape that have grapes maybe twice the size of the Cab. Francs. A similar taste test is performed, and the sweetness is incredible. If it wasn't for the seeds, you'd reach in and grab some more. Using a refractometer, I measured the Brix on the Seyval Blanc at 16, which if it was converted to alcohol it would only provide a little more than 8%. (NOTE: the actual conversion includes many factors, like what yeast was used. The true conversion can range from multiplying Brix x .55 to .61) The Cab. Franc registered just a 6 on the Brix scale....no wonder why it tasted bitter.
This year we also are seeing our first grapes from our Petit Verdot and our Cabernet Sauvignon. They deserve to have their Brix determined too, even though we expect a very small harvest. The bunches on the Cabs. are full and plump, a deep red, almost black coloring. While the red grapes in Block One are just turning color, from their grassy green to their final blue-red color, the Cabernet Sauvignon have already turned completely to their final shade. But how is their Brix ? One would think that they would be farther along than the Cab. Francs strictly based on the color, but the results prove they are at about the same sugar level at 5.5% The half percent is well within any margin of error, in as much as my sampling technique is rather weak because I don't want to waste valuable grapes to do a sampling many weeks before harvest.
We have looked over our past harvest data and have found that our harvests tend to begin about August 24th and last about a month. Whites first, followed by the reds. I suspect the Seyval Blancs will be right on schedule.....I was hoping maybe a little early but we just received a few days of rain to screw this up. Then the Viognier, followed by both Cabs., the Petit Verdot, and lastly the Nortons. We may actually get to pull some Scuppernongs this year too, but our experience with these grapes is rather on the light side so I have no idea when we will be picking them, though I am guessing later, not earlier.