Can wine be made without yeast?

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,
Can wine be made without yeast?
—Alfonza M., Whiteville, N.C.
Dear Alfonza,
No. The difference between grapes and wine is that a yeast consumed the sugar in the grapes and produced alcohol and carbon dioxide.
Now, you can sometimes make wine without adding any yeast. Eventually the native yeast in the air will do the conversion for you, and some winemakers produce wines this way, calling it a “native” or “wild” or “natural” fermentation. It can be tricky and doesn’t always work, depending on what kind of and how much native yeast you have. Most winemakers prefer to inoculate with a commercial yeast, which is much more predictable.
—Dr. Vinny