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Volume 90 Issue 4 | p. 48 | Newscripts
Issue Date: January 23, 2012

A Mouse In A Can, A Siphon For Your Brew

Department: Newscripts
Keywords: soda, enamel, teeth, hydroxyapatite, calcium phosphate, Mountain Dew, Pepsi, dentistry, acidity, coffee, siphon, vapor pressure
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Surprise!: A mouse wouldn’t stay whole for long in a soda can.
Credit: Wikimedia Commons/Shutterstock/C&EN
A man claims he found a mouse in his can of Mountain Dew; PepsiCo says it would have dissolved.
 
Surprise!: A mouse wouldn’t stay whole for long in a soda can.
Credit: Wikimedia Commons/Shutterstock/C&EN

Dentists often nag their soda-guzzling patients to lay off the soft drinks to prevent tooth erosion. Now the doctors have the ultimate argument-ending anecdote: PepsiCo says that a can of Mountain Dew could dissolve a mouse.

The company made the admission to defend itself against an ongoing $50,000 lawsuit filed by an Illinois man who claims he found a dead mouse in his can of Mountain Dew. According to the complaint he filed, Ronald Ball spotted the mouse only after he took a swig of the soda and “immediately became violently ill.”

Based on the can’s production date, PepsiCo estimates that the mouse would have spent 74 days in the drink. A veterinarian who examined the mouse for the company says there is no way the critter Ball found had spent that much time in the can.

The bones and organs of Ball’s mouse were still whole, according to the doctor’s affidavit. But at a pH of 3.4, the Mountain Dew would have leeched all the calcium from a submerged rodent’s bones in four to seven days, the doctor wrote. The rest of the mouse would have disintegrated into an unrecognizable “jellylike substance” after 30.

Poonam Jain, a professor of dentistry at Southern Illinois University School of Dental Medicine, agrees with the veterinarian: “It would have been impossible to find that mouse in pristine condition.” She points out that hydroxyapatite, the calcium phosphate mineral in teeth and bone, readily dissolves in acidic solutions. For tooth enamel, once the pH hits 5.5, the mineralized tissue starts to erode.

But a soft drink’s acidity alone doesn’t dictate how effectively it will dissolve the mineral, Jain says. In a 2007 study, she and her colleagues researched the enamel-dissolving abilities of 18 brands of soda. They found that although noncola drinks, such as Mountain Dew, were slightly less acidic than colas, such as Pepsi, the noncolas were more erosive. One possible explanation for the difference, Jain says, is that citric acid, the predominant acid in noncolas, chelates calcium more readily than can phosphoric acid, colas’ main harsh ingredient.

So science appears to be on PepsiCo’s side, but the details give new meaning to Mountain Dew’s old slogan: “It’ll tickle yore [sic] innards.”

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Brewing rig: A siphon coffeemaker.
Credit: Shutterstock
A siphon coffee maker.
 
Brewing rig: A siphon coffeemaker.
Credit: Shutterstock

After learning about the potential mouse in the soda can, some of the Newscripts gang have considered switching to coffee for their caffeine fix. But among the myriad coffee-brewing methods, only one also satisfies our love of lab glassware: siphon brewing.

The 19th-century method has recently gained popularity in trendy coffee shops. The setup consists of two pieces of glassware: a carafe and a glass chamber with a bottom spout that fits snugly into the carafe. Water goes in the carafe, coffee grounds go in the upper glass chamber, and the whole rig sits on a burner.

As the water reaches a boil, the vapor pressure pushes the water up the spout into the upper chamber, soaking the grounds. After a couple minutes of steeping, the impatiently waiting brewer removes the glassware from the heat. The carafe cools and the water vapor pressure drops, allowing atmospheric pressure to push and gravity to pull the brewed coffee back into the carafe. The liquid passes through a filter on the spout, keeping the grounds out of the coffee.

Siphon aficionados claim that the method produces a clean, smooth-tasting drink, but we just think it looks cool.

 
Chemical & Engineering News
ISSN 0009-2347
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