Does one moldy grape spoil the bunch?

Yes, one moldy grape can spoil the bunch, as mold can spread rapidly to neighboring grapes. Mold releases spores that can infect adjacent fruit, leading to further spoilage. It's generally advisable to remove any moldy fruit from a group to prevent the spread of decay. Thus, it's often said that "one bad Apple spoils the bunch," and the same principle applies to grapes.