Double Dipping Spreads Germs Dipping the same chip into a bowl of dip more than once has always been a questionable practice. Now, a study done at Clemson University shows that double dipping does spread germs.
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Double Dipping Spreads Germs

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Double Dipping Spreads Germs

Double Dipping Spreads Germs

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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(Soundbite of crunching)


You'll need sustenance to get through the big game today. So don't forget the chips and your favorite dip, whether it be guacamole, salsa, bean or cheese. But do not dip that chip twice. Paul Dawson, a professor of food microbiology at Clemson University, and his students conducted a recent study on the dangers of double-dipping. The research was inspired by an episode of Seinfeld.

(Soundbite of TV show, "Seinfeld")

Unidentified Man (Actor): Did you just double-dip that chip?

(Soundbite of laughter)

Unidentified Man (Actor): You double-dipped the chip.

Mr. JASON ALEXANDER (Actor): (as George Costanza) Double-dipped? What are you talking about?

Unidentified Man (Actor): You dipped the chip, you took a bite and you dipped again.

(Soundbite of laughter)

Mr. ALEXANDER: (as George Costanza) So?

Unidentified Man (Actor): That's like putting your whole mouth right in the dip.

HANSEN: Paul Dawson joins us from Clemson University. First, welcome to the program.

Professor PAUL DAWSON (Food Microbiology, Clemson University): Thank you very much.

HANSEN: What did you expect to find in your research on double-dipping?

Prof. DAWSON: I expected not to find very much bacteria transferred. But we were surprised that when the student dipped the chip and then put it back in the dip, it does inoculate, so to speak, that common dip area.

HANSEN: What dips did you use to test your theory?

Prof. DAWSON: We started with actually sterile water just to see if it would transfer. And when it did, we tested three dips, that being salsa, chocolate dip and then cheese dip. And sure enough, it followed suit that there was significant transfer of bacteria due to double-dipping.

HANSEN: Is it really more or less sanitary than kissing somebody or sharing a toothbrush?

Prof. DAWSON: I would say it's about the same. And most bacteria are good bacteria, are not harmful. On the other hand, we know that there are infectious diseases that are carried in saliva. It only follows that this might be another way that those are transferred.

HANSEN: So what's the solution for folks who are going to have their Super Bowl parties today? Should they just steer clear of particular dips?

Prof. DAWSON: Well, you said a couple of things earlier. That one would be you look around the room and if people are double-dipping, if you're willing to kiss everybody in the room, then go ahead. Or if you prefer not to, then maybe avoid that dip.

(Soundbite of laughter)

HANSEN: Are you doing anything Super Bowl Sunday?

Prof. DAWSON: I've actually been invited over for some other colleagues to have a Super Bowl party, yes. (unintelligible)

HANSEN: What are you going to bring?

Prof. DAWSON: I'll be bringing some sanitizer and - no. I think we're bringing some dip.

HANSEN: What kind of dip are you bringing?

Prof. DAWSON: Spinach artichoke dip, small chips, rubber gloves.

(Soundbite of laughter)

HANSEN: And antibiotics?

Prof. DAWSON: Toothbrush. Yeah, I mean…

(Soundbite of laughter)

HANSEN: Paul Dawson is a professor of food microbiology at Clemson University in South Carolina. His study on double-dipping will be published later this year in the Journal of Food Safety.

Thanks for your time.

Prof. DAWSON: Thank you very much.

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