Sometimes you want to put a little more salsa on your half-eaten chip, but should you consider dipping it back again? Is double dipping simply a bad manner, or are you actively contaminating communal snacks with your particular germs? When you double dip you actually transmit the bacteria from your mouth to the bite and then into the dip. This is fine if it’s your own bowl of chips and dip. However, if you are somewhere in the social gathering, double dipping is considered as a poor move and a sign of poor hygiene. It is unsurprising if you get some anger thrown your way if you decide to do so.
There are scientific as well as social reasons why you should stop the practice of double-dipping. Let’s look into the science behind it to find out what happen when you double dip.
Near around 100-1000 different types of bacteria and viruses live inside the human oral cavity, most of which are harmless. But some are not good. Tuberculosis, influenza virus, Legionnaires’ disease and severe acute respiratory syndrome (SARS) are known to spread through saliva, coughing and sneezing. When a person sneezes or coughs, these germs get transferred through tiny droplets and settle down on surfaces like utensils, door, desks and doorknobs. When a person touches these contaminated surfaces and then touches his eyes, nose or mouth he becomes infected. The same happens when you double dip. Germs from your saliva get entered into the dip and when your partner dips his share in the same bowl he invites the bacteria and this way double dipping leads to the spread of oral bacteria from person to person. And a person doesn’t have to be sick to pass on germs!
To more closely analyze what happens during double dipping, an undergraduate team of researchers at Clemson University designed a series of experiments to see if there is indeed bacterial transfer during the double-dipping process – and if so, how much bacteria makes it from mouth to dip. The team started comparing bitten versus unbitten crackers and found that there was a substantial difference in the number of bacteria between a fresh cracker and the cracker that had been bitten once and then returned to the dip.
Also, the role of dip’s acidity and viscosity was analyzed and it was found that a combination of viscosity and acidity determine how much bacteria gets into the dip from double-dipping. The more acidic a dip was, the lesser was the possibility of bacteria growth and vice versa in context of viscosity. Salsa being more acidic and less viscous had 5x more bacteria than chocolate and cheese dip.
Yes, there is a cause to have concern about double dipping with strangers. Don’t do it, and don’t do it yourself for best results. It is more than a bad etiquette. Be a good friend and eat it all in one bite.
Caution: Be prepared to get some rightfully deserved hate when you decide to double-dip!