How does the quality of grapes affect the quality of wine?
If it rains when they're picking, what happens is that the grapes, because of the moisture and such, it will be a thinner wine and there will be a tinsy for more rot and all these are reflected in the wine itself. You need great grapes to make great wine. A great wine maker cannot make greatness unless he has the materials to work with. If he has great grapes he can muck it up. But if he has a great winemaker and he has lousy grapes there's not much he can do.