You might wonder how badly frying a Thanksgiving turkey could go—especially while standing next to a fryer filled with four gallons of screaming-hot peanut oil, holding what you hope is a completely defrosted bird. The answer is real bad. And there’s an exhaustive list of YouTube videos made by local fire departments to prove it. Thing is, if something goes wrong, it’s not bad luck. There’s a scientific reason why a deep-fried turkey explodes, catching your yard—or worse—on fire.
It’s all about the differences in density, says Kristine Nolin, an associate professor of chemistry at the University of Richmond. The density differences between oil and water, as well as the differences in density between water in its solid, liquid, and gas states can lead to explosive results, Nolin writes in The Conversation, an online, independent news organization.
Why a deep-fried turkey explodes
Raw turkeys contain about 75 percent water. In a frozen turkey, that becomes a lot of ice. When a frozen turkey is submerged in 350˚cooking oil (much hotter than water’s boiling point of 212˚), that ice quickly becomes water.
Since liquid water is denser than oil, it goes to the bottom of the hot pot where it absorbs more heat and energy. It’s at this point that water turns to steam, expanding its volume by 1,700 times. This expanding steam blows the boiling oil out of the pit where it can hit the open flame and catch fire. Droplets of oil catching on fire then ignite neighboring oil molecules, causing a big bang of sorts.
It’s not just deep-fried turkeys. The U.S Fire Administration notes Thanksgiving Day is when most cooking fires happen. Between 2017 and 2019, an average of 2,300 residential building fires happened on the holiday, with an average of five deaths, 25 injuries, and $26 million in property loss.
If you do want to fry a turkey, the U.S. Department of Agriculture (USDA) advises the bird be thawed completely and you never leave hot oil unattended. In addition, the Federal Emergency Management Agency (FEMA) says to make sure you put the fryer on level ground at least 10 feet away from your home and not under eaves. Don’t overfill the fryer with oil. And always keep an all-purpose fire extinguisher nearby.