Double-dipping a chip is officially disgusting, science confirms

Scientists confirm that double-dipping a chip is not OK, not cool and not very healthy for anyone involved.

The chip double-dip is not OK, not cool and not very healthy for anyone

At least one fictional man became so irate over double-dipping that he attacked another fictional man at a fictional 1993 funeral in Detroit. (YouTube/NBC)

The practice of "double-dipping" chips can be as contentious among groups of people as the very flavour of chips considered best. (Ketchup. Ketchup chips are the best.)

Some people, like Seinfeld's George Costanza, see no problem in dipping a chip, taking a bite, and dipping again to ensure that each bite contains the snacker's preferred ratio of dip to chip.

Others, like Costanza's one-time girlfriend's brother Timmy, is strongly opposed to the double-dip.

As he told George at a funeral during an episode of the show that aired in 1993, "that's like putting your whole mouth right in the dip!"

With apologies to Team George, it appears as though there may be some crumbs of truth behind Timmy's argument. 

An undergraduate research team at Clemson University in South Carolina recently looked into the age-old quandary of whether or not double-dipping is OK from a hygienic perspective.

To do this, they conducted a series of experiments aimed at determining how much bacteria can be transferred between bitten crackers and dips of varying acidity levels.

"Members of the no-double-dipping enforcement squad, prepare to have your worst, most repulsive suspicions confirmed," wrote Clemson food science professor Paul Dawson in a piece about the results this week.

As it turns out, his team found about 1,000 more bacteria per millilitre in cups of water that had been penetrated by bitten crackers than in the cups of water students had tested with unbitten crackers.

Both bitten and unbitten crackers were then dipped into actual food dips to see if similar patterns presented themselves.

They did.

Intrigued by the question of whether or not double-dipping is a 'food safety problem' or 'just a nasty habit', Clemson University food science students looked at the bacteria levels of dips hit with bitten vs. unbitten crackers. (Paul Dawson/Clemson University)

"We compared three kinds of dip: salsa, chocolate and cheese dips, which happen to differ in pH and thickness," Dawson explained. "We also tested the dips two hours after dipping to see how bacterial populations were growing."

In the absence of double-dipping, no detectable bacteria were present in any of the dips.

Dips that had been hit with already bitten crackers, on the other hand, were swarming with germs.

"The salsa took on about five times more bacteria (1,000 bacteria/ml of dip) from the bitten chip when compared to chocolate and cheese dips (150-200 bacteria/ml of dip)," wrote Dawson, explaining that this likely has to do with the lower viscosity of salsa.

"Chocolate and cheese dips are both pretty thick. Salsa isn't as thick," he said. "More of the dip touching the bitten cracker falls back into the dipping bowl rather than sticking to the cracker. And as it drops back into the communal container, it brings with it bacteria from the mouth of the double-dipper."


Citing the CDC's recommendations involving the prevention of influenza, whooping cough and other infectious diseases, Dawson suggests that there is reason to be concerned about someone spreading oral bacteria through double-dipping.

So, from now on, when you take a chip, you should probably just take one dip and end it.


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