Making small talk at holiday parties is bad enough for most people. But what if some stranger just went ahead and shoved their whole mouth into the hummus right before you even got a dip?
That's basically what happens when you double-dip, according to a new report from an undergraduate research team at Clemson University. Trying to figure out if the bacteria from your mouth can be transferred on a chip and if the acids in said dip might counteract any potential contamination, they did a series of dip-speriments in compiling the scary-sounding report, "Effect of Biting Before Dipping (Double-Dipping) Chips On The Bacterial Population Of The Dipping Solution."
We'll spare you the suspense: it's gross.
Researchers, armed with chips and crackers, tried three different experiments to test their hypothesis. The first group dipped 3-6 crackers into sterilized water either "without biting or biting before each dip." As you might expect, the solutions in that test (and the second one) had higher bacteria counts when dippers doubled-down than when they didn't, with the bacteria levels dropping after two hours in the dips with the lower PH levels.
In the third test, using salsa, chocolate sauce and cheese, they found more bacteria leeching into the salsa than the other two dips at first, at a rate five times higher than the other two solutions. But after sitting for two hours, the levels in the salsa went down because of the high acidity in the dip and the bowls that were not double-dipped had no detectable traces of bacteria.
At any given time there are hundreds or thousands of kinds of bacteria in your mouth, the majority of them pretty harmless. But it's the ones that are dangerous, like the flu, TB or SARS that you should be worried about if you touch a contaminated surface and then your eyes, nose or mouth.
Here's the take-away: "Three experiments determined that the bacterial population of food dips increased due to the practice of 'double-dipping,' and that dip type can influence the dip's bacterial population."
So when you're at that party and you spot a double-downer hitting the salsa hard, you can either walk away entirely, or chill for a while and let the bacteria simmer down.