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,
Why do Champagne bubbles come from the bottom of my glass?
—Jen, Pleasanton, Calif.
The bubbles in Champagne and other sparkling wines are made of carbon dioxide gas. Fun gas trivia: carbon dioxide is more soluble in colder liquid. That’s why if you open up a warm bottle of bubbly (or can of beer or soda) lots of the gas escapes all at once in a volcano of fizz.
In a wineglass, carbon dioxide bubbles form at what are called “nucleation sites,” or tiny scratches or imperfections in the glass. The gas gathers at these sites until it forms a bubble and then escapes upward. Many wineglasses made for sparkling wine have such nucleation sites intentionally scratched into the bottom of the bowl of the glass to facilitate an elegant bead of tiny bubbles (these days they are typically etched by lasers). But anything can create a nucleation site for bubbles, even a speck of dust.