White mildew on grapes

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Active Member
Aug 31, 2022
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A very friendly neighbor graciously let me harvest their grape vine since they weren't using it, which is awesome. However, since they weren't taking care of it, the grapes have some pretty widespread powdery white mildew on them. I washed them with water before freezing them but it's difficult to get it all off. Will it be much of a problem? Would any risks it poses be fixed with a crushed campden tablet in the must anyway? They tastes fine themselves.

Also, something mildly interesting, the there's actually two vines, one has green grapes and one with dark blue grapes, and though they're pretty intertwined only the dark grapes have the mildew on them.
I'm not positive on the species, I live in the PNW, I think they're just two different types of concord? Either that or the green one is riesling. No idea really, just going off of cursory research.