31 December 2014

Champagne and rain have something in common and it isn’t that they’re both wet.

While toasting the holiday with a glass of champagne I wondered, Why do champagne bubbles rise from discrete points inside the glass?

Champagne is carefully fermented under pressure so that carbon dioxide is absorbed into the liquid.  When you open a bottle of champagne the CO2 is released.   This can be beautiful or boring depending on the glass you use.

The bubbles perform badly in a plastic ‘glass’ (they won’t rise off the sides) and perform best in a tall thin champagne flute because it concentrates them into less surface area.  They will rise from a single point where there’s a dust mote in the liquid or a tiny nick inside the glass.  For this reason some glass makers purposely put tiny scratches, called artificial nucleation sites, in the bottoms of their champagne glasses to make bubble patterns.

What do champagne and rain have in common?

Champagne bubbles form around dust motes or nicks in the glass.  Raindrops form when water vapor condenses around tiny dust motes in the cloud. They both use a tiny “flaw” to get them going.

Learn more at:

• Deutsch Welle: The science of champagne and 
• American Physical Society: How Raindrops Form.

(photo in the public domain from Wikimedia Commons, enhanced to highlight the bubbles.)