London - It is a matter of modern etiquette: to double-dip or not to double-dip?
By re-dipping your half-eaten crisp, cracker or crudité after taking a bite out of it, you are guaranteed more of the tangy salsa or tasty houmous.
But by taking the plunge for a second time, you also risk being branded bad-mannered or just plain greedy.
Now, it seems that it is not just etiquette that is under the microscope.
Medics say that double-dipping spreads germs, potentially putting other dippers at risk of illnesses from flu to whooping cough.
In his review of the evidence Robert Shmerling, a Harvard University doctor, focused on a study in which food scientists analysed how much bacteria was on a crisp before and after double-dips.
He found that contamination soared – in fact. three to six immersions of a bitten cracker managed to transfer about 10 000 bacteria from the mouth to the dip.
And the researchers, from Clemson University in South Carolina, estimated that double-dipping at a real party would typically transfer 50 to 100 bacteria from person to person per bite.
Those who are about to attend a barbecue will be interested to know that bugs thrived more in salsa than chocolate or cheese dips.
It is thought that because the salsa was runnier, more of it slipped off the crackers and back into the bowl – taking mouth bugs with it. The study, published in the Journal of Food Safety, was inspired by a storyline in the TV series Seinfeld, in which the hapless George Costanza was caught double-dipping at a wake.
A fellow mourner shamed him, saying: “That’s like putting your whole mouth right in the dip.” The scientists said that the mouth is home to up to 1 000 types of bacteria – including strains that can be “life-threatening”.
They added: “Therefore, the practice of double-dipping may have more relevance than just popular interest. This ‘bad habit’ may also have negative health implications.
“Individuals sharing a dip may be passing disease-causing agents, yet not show outward signs of illness.”
But in his article, entitled Double-dipping Your Chip: Dangerous Or Just Icky, Dr Shmerling said you are more likely to contract an illness from someone coughing or sneezing in your face.
He does, however, have some advice for those who can’t resist returning to the dip. He said: “I wonder about a more responsible option: turn the chip around to double-dip from the unbitten end.”
Daily Mail