It's Scientific: Beer Bubbles Do Sink
Mar 22, 2004 - Yes, it's now been proven scientifically: beer bubbles can go down as well as up. Scottish scientists claim to have captured on video evidence that proves that bubbles in a glass of beer can move downwards. The Edinburgh University researchers used a high-speed digital camera to record the movement. By no small coincidence, the evidence was released to coincide with St Patrick's Day, claiming that the effect is clearest in Irish stout. Sure, beer drinkers have claimed for years that they've seen bubbles sink to the bottom of their glass, but scientists had never really proved that it could happen. Now, scientists behind the joint Edinburgh University and Stanford University project said their study had given definitive proof. They found that bubbles touching the walls of a glass experience drag, and the drag prevents them floating upwards, while bubbles in the middle of the glass are free to rise. The result is a circular flow, which causes the bubbles near the edge of the glass to be pushed downwards, and was most observable in a dark beer like stout, as the contrast between dark liquid and creamy bubbles in stout made it most suitable for their research. The researchers employed an undisclosed quantity of beer in the experiments, but they insist that it was poured away afterwards to prevent any possible impairment of their judgment.