What makes grapes uniquely suited to making wine?

Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.
Dear Dr. Vinny,
Although alcoholic beverages have been made from many fruits (most of them bad), what makes grapes uniquely suited to making wine?
—J.J., Winnipeg, Manitoba
Dear J.,
Grapes are pretty unique in that they have the balance of sugar, acidity and tannins to make wine so complex. Other fruits can be too acidic, or too sweet and not acidic enough. When folks make wine from other fruits, they tend to add water or sugar (or both) to get it in balance. Grapes also require less fuss when it comes to the fermentation process—they can naturally convert their sugar into alcohol—while other fruit sources lack the nutrients to make this happen easily.
—Dr. Vinny