Good reason to have listened to you mum when she said "dont double dip" http://www.theaustralian.news.com.au/story/0,25197,23138250-12377,00.html By staff writers | January 31, 2008 DOUBLE-dipping, a practice frowned upon by many around snack tables at parties, is a major health hazard, according to a new US study. The study, to be published this year in the Journal of Food Safety, was inspired by an episode of the comedy show Seinfeld. In the show, character George Costanza is confronted at a funeral reception after dipping the same chip twice. Clemson University food microbiologist Paul Dawson said he proposed the study to get undergraduate students involved in scientific research. The team of nine students had volunteers bite a wheat cracker and dip the cracker for three seconds into a tablespoon of dip. They repeated the process with new crackers, for a total of either three or six double dips per dip sample. The team then analysed the remaining dip and counted the number of aerobic bacteria in it. The students found that on average, three to six double dips transferred about 10,000 bacteria from the eaters mouth to the remaining dip. Each cracker picked up between 1-2g dip, meaning sporadic double-dipping in a cup of dip would transfer at least 50 to 100 bacteria from one mouth to another with every bite. "The way I would put it is, before you have some dip at a party, look around and ask yourself, 'would I be willing to kiss everyone here?' Because you dont know who might be double-dipping, and those who do are sharing their saliva with you, Professor Dawson told the New York Times. Prof Dawson encourages his undergraduate teams to test popular conceptions about food safety. Last year he published a paper on the five-second rule, which states that food dropped on the floor can be safely eaten if you pick it up before you can count to five. The rule turned out to be false.