Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: Greg on 23/03/2009 14:30:02

Title: Why does oil from skin reduce the head on beer?
Post by: Greg on 23/03/2009 14:30:02
Greg asked the Naked Scientists:
   
If you rub your finger on the oil next to your nose then stir your finger into
beer froth, why does the froth diminish, allowing you to pour more  beer into your mug?

What do you think?
Title: Why does oil from skin reduce the head on beer?
Post by: DeepestBlue on 21/04/2009 00:50:34
OK hypothesis from an ignorant Architect.....the froth, or small bubbles exist because of the surface tension of the water in the beer.  When the oil is added (it may not be oil, it might be....euuuch never mind...), the surface tension of the liquid reduces and can no longer contain the pressure of the bubbles, hence the bubbles burst, and the head reduces in size.....
Title: Why does oil from skin reduce the head on beer?
Post by: Don_1 on 21/04/2009 08:53:05
That sounds pretty good to me DeepestBlue.

Can I just ask, Greg, why do you rub your finger around your hooter then stir your beer with it? I can think of better things to do with a pint of beer, like drink it and better things to do with a finger, like (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.freesmileys.org%2Fcustom%2Fcreate.php%3Fid%3Dbrown%255E_%255Earial%255E_%255E0%255E_%255E0%255E_%255E%252A%252A%252ACENSORED%252A%252A%252A%255E_%255E.gif&hash=637b2d3511fadb43b3c77acd2ce9e01a)