Bad Grapes...

 My grapes are going bad,rather than ripening.
They are supposed to be concords,and are still sour when I eat them.
Any ideas on what I'm dealing with?

Yours look about like mine right now. Concords are a purple grape so yours are GREEN and not ripe yet.

I have a 'green' eating grape and they will turn more of a red in the fall and are a zillion times better red and ripe.

I will lose a few to shrivel, spots, and bugs between now and purple.

Edit, I'm in 6b and my concords will be ripe in another month to six weeks. I try to let them go as late as I can without them shriveling as they get sweeter as they go, and usually pick between mid September and whenever they offer we'll get frost.

It looks to me that your grapes that appear to be ripening are victims of fungus. Check out black rot.
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/fruit-spots/black-rot-of-grapes.aspx

Thanks Joylynn,for thediagnosis and the great resource!