Buzz
Chips and dip are the go-to quick snack for social events: grab a bag, plate them, and you're set. But the act of biting into a chip, then returning it to the dip—known as double-dipping—seems like a sure way to spread germs. After all, we don’t casually take bites from someone else’s hand, so why is this practice accepted?
Ali Francis, in an investigative piece for Bon Appétit, reached out to several experts on the matter. Among them was Paul Dawson, PhD, who in 2009 conducted a study that might just be the ultimate exploration of whether double-dipping is a hygienic choice. The verdict: It’s gross.
Dawson ran a series of tests to measure how bacteria transfer from a person’s mouth into a shared bowl—in this case, a glass of water. An untouched cracker barely introduced any germs to the water. But once bitten, it contaminated the water with 1000 more bacteria per milliliter.
Since we don’t typically snack on chips with water, Dawson expanded his research to include the transfer of bacteria from bitten and unbitten crackers into various dips, like salsa (specifically Tostitos Extra Chunky, if you're curious) and cheese. The dips were bacteria-free before being dipped into. However, after a double-dip, the bacterial count in the dips surged by up to five times, showing that crackers act as a conduit for germs from our mouths to the dips.
It’s harder to determine if those germs will cause harm. Every mouth carries some bacteria, but it may not always be an issue. At other times, our mouths might be home to contagious diseases, such as the common cold, flu, and COVID-19. If someone with harmful bacteria double-dips, others could unknowingly ingest bacteria like staph with their Tostitos.
Dawson noted that the type of dip used also plays a role. Salsa, which is more acidic, is less friendly to bacteria. However, its thin consistency means the dip is more likely to slide off a cracker, contaminating the entire bowl. On the other hand, thicker dips can make it harder for bacteria to spread around. A person might double-dip on one part of the cracker, leaving the opposite side of the bowl somewhat safer.
So, how much should you really worry? If you see someone with clear symptoms of illness double-dipping, it’s best to steer clear of their dipping bowl. Ideally, they shouldn't be at the party to begin with. (Though asymptomatic people can spread trouble too.) Otherwise, you can accept that some bacterial transfer is inevitable and carry on. Dips may have germs, but so do doorknobs, bathrooms, spice cabinets, and the couch where that one guy keeps sneezing.
Still feeling uneasy? You could try arriving early, using a spoon to scoop some dip onto your plate, and setting up your own dipping station. Hosts might also consider offering smaller chips or crackers to encourage single-dipping.
