There’s an old Seinfeld episode where George double-dips a chip at a funeral. Immediately, his girlfriend’s brother jumps in his face and says “that’s like putting your whole mouth right in the dip!” Nevertheless, George refused to stop double-dipping (not surprisingly), but should you?
Double-Dipping:
A new study tested to see whether double-dipping does in fact transfer bacteria from a person’s mouth to a dip. Participants either dipped without taking a bite or double-dipped into a salsa, chocolate or cheese dip. The researchers found virtually no bacteria in the dips that had not been double-dipped. However, there was a significant amount of bacteria in the double-dipped dips, with the salsa containing 1,000 bacteria/ml!
This should be of concern because previous studies have found that saliva droplets can transmit pneumonic plague, tuberculosis, influenzas, Legionnaires’ disease and severe acute respiratory syndrome (SARS).
Conclusion:
Double dipping significantly increases the risk of harmful bacteria transfer from one person to another. If you’re a double-dipper yourself, try to stop. If you’re at a party, steer clear of the community dips unless you’re one of the first ones there.
Citation:
Trevino, Judith, et al. “EFFECT OF BITING BEFORE DIPPING (DOUBLE‐DIPPING) CHIPS ON THE BACTERIAL POPULATION OF THE DIPPING SOLUTION.” Journal of food safety 29.1 (2009): 37-48.