Why Koozies Keep Your Beer Cold
April 26, 2013

Koozies Scientifically Proven To Be Your Best Protection Against Warm Beer

Michael Harper for redOrbit.com — Your Universe Online

Countless theories on the best way to quickly cool down a beer (or soda for the teetotalers) have been formed in the past, some of which were even put to the test by the MythBusters. But just as important as cooling beer is the challenge of keeping it cold, an aspect which is suspiciously absent from these frat-born theories.

According to a new study published in Physics Today, a koozie is the best defense against condensation and humidity, two factors which work together to gradually warm your beverage. Dale Durran, professor of atmospheric sciences at the University of Washington (UW), co-authored this timely study and now sings the praises of the beer koozie.

“Probably the most important thing a beer koozie does is not simply insulate the can, but keep condensation from forming on the outside of it,” Durran explained.

According to this new study, humidity and the resulting condensation can warm your beer quicker than high air temperatures. In typically humid climates, heat released by condensation can warm a beer by 6 degrees Fahrenheit in only five minutes. This means a near-freezing beer pulled fresh from the cooler in Florida will warm to nearly 50 degrees Fahrenheit in less than ten minutes.

Durran began this investigation a couple of years ago when he began looking for examples to explain the way condensation can work to generate heat. There were plenty of examples to demonstrate evaporative cooling, the exact opposite of this effect, but Durran wanted something specific to show his Atmospheric Sciences 101 students at UW. He predicted the sweat droplets on a can of beer would be the very example he was looking for. After performing some quick math, he calculated that even the a little bit of condensation can heat a beer by nine degrees.

“I was surprised to think that such a tiny film of water could cause that much warming,” he said.

To study this effect, the professor set up a small test rig in a rarely used bathroom in the basement at UW. Durran and fellow co-author and UW professor Dargan Frierson used a space heater and a shower to adjust the levels of heat and humidity in the bathroom. Once the duo was able to document their findings on a small scale rig, it was time to move to something larger.

“You can´t write an article for Physics Today where the data has come from a setup on the top of the toilet tank in one of the author´s bathrooms,” joked Durran.

The professors recruited some undergraduate students and began testing the effects of the atmosphere on beer cans in different regions, including the dry climate of Seattle and the humid beachside climate of Wilmington, North Carolina. In each test, the researchers found humid climates create more condensation, and more condensation means a warmer beer.

This effect can be observed elsewhere in the kitchen as well. For instance, when moving a hot skillet from one burner to another or pulling a hot pan from the oven, it is always important to use a dry towel or potholder. As anyone who´s ever used a wet towel can attest, the heat is transferred from the pan to your hand almost instantly. In the beer example, the outside air acts as the hot pan and the can of brew as your hand. Keeping a can of beer dry and protected by a koozie prevents the condensation from acting as a wet towel and burning your suds.

According to Frierson, we could all be in for a world of warm beer thanks to global warming.

“We expect a much moister atmosphere with global warming because warmer air can hold a lot more water vapor,” said Frierson in closing.

This means the most important thing you can do for your beer as the days grow warmer is to pick up a stash of koozies and keep one nearby at all times.