Engineering Innovation Podcast and Radio Series

Beer Bubbles

PostedMarch 11, 2005

Download File (mp3)

Richard Zare, a Stanford professor, didn't just stare longingly into his beer last Saint Patrick's Day.  He videotaped it and discovered that enthusiastically rising bubbles in the center of your beer not only create a nice head of foam, but push bubbles near the glass edge downward.  Zare's experiment is now providing a better understanding of a process called "froth flotation."  In your beer, it separates some flavor chemicals, making the foam a bit bitter and the liquid sweeter.  But it also has numerous engineering applications.  Zare says one of the most recent may allow much more efficient recycling of plastics.  With the National Academy of Engineering, Randy Atkins, WTOP Radio.