This has to be a first: A serious scientific research project was conducted based on an episode of "Seinfeld."
Clemson University food microbiologist Paul L. Dawson was watching a rerun of a 1993 episode of "Seinfeld" in which George Costanza is confronted at a funeral reception by Timmy, his girlfriend's brother, after dipping the same chip twice. "Did, did you just double-dip that chip?" Timmy asked George. "That's like putting your whole mouth right in the dip!" George retorts, "You dip the way you want to dip, I'll dip the way I want to dip."
So can double-dipping really hurt you? Dawson decided to find out, expecting there would be little or no microbial transfer from mouth to chip, reports The New York Times. Not so! He and nine students recruited volunteers and asked them to each take a bite of a wheat cracker and dip the cracker for three seconds into a tablespoon of test dip. Six dips were used: sterile water with three different degrees of acidity, a commercial salsa, a cheese dip and chocolate syrup. They repeated this using new crackers so that each dip sample had three or six double-dips in it. The Clemson team analyzed the dip to count the number of aerobic bacteria in it.
The results: On average, the students found that three to six double-dips transferred about 10,000 bacteria from the eater's mouth to the remaining dip, reports The Times. So if people sporadically double-dip into a cup of dip, at least 50 to 100 bacteria are transferred from one mouth to another with each bite.One important note: The type of dip makes a difference. The more acidic the dip, the fewer the bacteria; however, the runnier the dip, the more bacteria are left behind. "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?" Dawson told Times reporter Harold McGee. "Because you don't know who might be double-dipping, and those who do are sharing their saliva with you."
Link to the original article.