Food expert reveals 'gross' unexpected reason why you should never double-dip

As tempting as it may be, you should avoid double-dipping your food - and here’s why.

For some foodies, double-dipping is simply part of the process of tucking into snacks. But for others, double-dipping is a major faux pas that makes any sane person shudder at the thought of bacteria from the mouth intermingling with food, such as a shared dip.

There’s also a very specific reason as to why you shouldn’t double dip.

Not only can it be quite gross if you’re sharing a dip with other people, it can also affect the texture of the food.

A food writer was confused about why leftover oatmeal became a watery mess after a few hours. This oatmeal’s texture was completely different to the untouched leftover oatmeal in the pot from the same morning, which was still thick.

The food expert noticed something peculiar about leftover oatmeal (Getty Stock Image)

Naturally, food expert Swetha Sivakumar used the internet to search for answers and one key question kept coming up - did you double dip into the food?

Sivakumar did an experiment to find out how double-dipping seemingly changed the consistency of the leftovers which showed “the important digestive powers of saliva”.

Writing in Serious Eats, Sivakumar explained: “Without saliva, eating and digesting would be a lot harder, and less effective. The mucus in saliva, for example, is essential to swallowing. When we chew, the mucus and water in saliva transform dry or crumbly food into a soft, sticky lump called a bolus, making it easier to swallow.

“This helps prevent choking and protects the oesophagus from damage caused by rough food particles.”

However, mucus is not the key point in this example. Mucus is made up of 99% water and 1% of a mix of mucus, proteins, and electrolytes. Among the proteins are enzymes that help to break down food as you chew and munch on it.

Amylase is the ‘most abundant’ enzyme in saliva and is ‘critical’ when looking at why foods become thinner when double-dipping.

Double dipping is more common than one may think (Getty Stock Image)

Amylase works by breaking down carbohydrates, or starches, into simple sugars. The process starts in the mouth and it continues outside the mouth too.

Sivakumar tested starch-thickened dishes including oatmeal, cream of mushroom soup, cream of potato soup, cheese sauce, and creamy mac and cheese.

One set of starchy foods were untouched as a control, with another set where the food expert ‘licked a spoon and swirled it around the foods’. This licking and swirling process was repeated and after 15 minutes, the results were examined.

The 15-minute slot was chosen because researchers estimate that salivary amylase remains active in the body for about this time before the chewed and swallowed food before its treated with gastric juices.

It’s also roughly how long it takes to finish a meal, the expert said. All the foods were kept at room temperature.

As for the results?

Are you guilty of double dipping? (Getty Stock Image)

It took a mere five minutes to see thinning in the mushroom and potato soup and by the 15-minute time frame, the results were ‘quite significant’ for both the soup and oatmeal.

“Salivary amylase had a clear impact on the texture of these three foods in a brief window of time," Sivakumar explained.

However, the cheese sauce and mac and cheese showed ‘very little to no change’.

The expert said: “Since saliva doesn’t contain enzymes that break down proteins, this might have limited the effect. Double-dipping should be avoided in case your saliva gets into the food and alters its texture (and it’s also gross)."

The expert concludes: “But if you find a suspiciously runny soup, porridge, or roux-thickened sauce or dip in the office refrigerator or at a holiday party, you might want to stay away… because the enzymes from someone's spit have been hard at work.”