So I have a couple of my old vines that don't seem to be able to ripen more than 17 brix. I wrote down the day that veraison started, then checked sugar 2 weeks later it was at 17, 2 weeks afterwards it had not moved and I had a family wedding come up so 1.5 weeks after that it's still at 17. Vines are 40 years old. Can I just assume at this point that no further ripening will take place? I'm wondering if the age of the vines is playing into it as they are vinifera wine grapes.