Mechanical engineers have devised a technique for dunking biscuits in hot tea that ensures they do not end up at the bottom of the cup.
According to a mathematical formula, the best dunking is done with a full cup at a shallow enough angle to ensure the top surface of the biscuit remains as dry as possible.
Dr Len Fisher, who led the research team from Bristol University, used a gold-plated digestive to investigate andconcluded that the perfect dunk should be followed by smoothly twisting the biscuit 180 degrees, so that the dry side supports the weaker, soaked side.
People enjoy dunking because it releases about ten times the flavour of the biscuit compared with eating it dry, Dr Fisher said. Tests in the research, paid for by McVitie's, demonstrated that a post-dunk ginger nut is twice as strong as a dry digestive.