Pinot noir berries shrivelling

[GeoffMcG]

My grapes are a few weeks from harvest but many of the berries are staring to shrivel/dehydrate.
I have had fruit set issues this season due to the weather and hence have bunches with a mixture of large and small berries.
The small berries seem to be more affected than the larger berries but I'm worried about the problem spreading to the whole bunches before its time to harvest.
It's been a very humid season but with very little rain so I'm thinking it could be botrytis or simply dehydration.

Any ideas?

 

[BigH]

Have you measured pH and sugar? Where are they at? Sample both big and little berries.

It is difficult to tell from the pics if this is normal evaporation and shrinking, or if it is the beginning of losing a crop to black rot. If it is evaporation, then it is probably time to harvest, which I why I asked for the chemistry. Curious if the shriveled berries are over ripe.

PS: I don't grow pinot, and know nothing about it.
H

 

[FlamingoEmporium]

Havent grown grapes since I moved from NY 12 years ago, but it doesn’t look like disease. I have seen it before due to wild swings in weather extremes.

 

[GeoffMcG]

Thanks for your comments.
I have looked more closely and agree it's not disease, the smaller berries are just over ripe.
I sampled as BigH suggested
Large berries Brix 20
Small berries Brix 26.5
I'm going away for 3 weeks (bad timing) so decided to harvest half of the grapes now to make Rose and leave the rest until I return. I selected mainly affected bunches. The weather is cooling down now so hopefully the remainder will still be ok when I get back.
The numbers are Brix 22, pH 3.3, TA 0.95
Thanks again