We all love our chips and dip. Corn, potato, pita chips paired with a bowl of guac, pico de gallo, hummus — YOLO — it’s a classic anytime snack and a go-to for any social gathering. Now, most of us know better than to double-dip our chip. Obviously it’s not sanitary to put your personal chip back into the communal dip area once you’ve already coated it in saliva. If you’re a chronic double-dipper/trash person, we’re not sure if anything will convince you to change your ways, but hear out what science has to say about this nasty habit.
After rewatching the “Seinfeld” episode in which George Costanza is chewed out for double-dipping, Paul Dawson, a food scientist at Clemson University, decided to test just how filthy double-dipping actually is.
In the first experiment, he and his team tested single and double-dipped chips to see how much bacteria would transfer to a cup of water, for starters. Umm, a thousand more! The cup of water which had been double-dipped into contained a thousand more bacteria per milliliter of water. Woof.
Then they compared three different types of dips to see if pH balance and viscosity made a difference in bacteria count. They double and single dipped chips into a Tostitos chunky hot salsa, Hershey’s chocolate syrup and Fritos cheese dip, then tested for bacteria.
The dips which had been single-dipped into had no trace of bacteria. Double-dipped salsa was found to have five times more bacteria (1,000 bacteria per milliliter of dip) than the chocolate and cheese dips ((150-200 bacteria/ml of dip). Dawson theorizes that because the salsa isn’t as thick as the chocolate and cheese, “more of the dip touching the bitten cracker falls back into the dipping bowl rather than sticking to the cracker,” as he wrote in the Scientific American.
After sitting out for two hours, the salsa’s bacteria count dropped to the same as the chocolate and cheese dips — likely because the acidity killed off some of the microbes, according to Dawson.
Besides the gross factor of knowing you and your friends’ mouth bacteria is swimming around and multiplying in the dip bowl, remember that it can spread diseases, from the flu to herpes to legionnaires’ disease. So please, at your next hang, please dip your chip like a grown-up so we can all enjoy our favorite snack without getting sick.