In the midst of scorching summer days, when we don't want to turn on the stove, we sometimes wonder: Can you really fry an egg on the sidewalk? It's an age-old curiosity that has persisted for decades, fueled by online anecdotes and occasional scientific experiments.

But is it actually possible? Let's break down the science behind this sunny-side-up sensation.

How Hot Does It Need to Be Outside?

Contrary to popular belief, it simply being a hot day isn't sufficient. A dry heat is much more functional than humid weather. And, according to Nenad Miljkovic, a professor at the University of Illinois Urbana-Champaign, air velocity may also impact the experiment because surfaces won't get as hot due to the wind.

"The air usually doesn't reach above 110 or 115 degrees Fahrenheit, but if there's a surface that can absorb solar light, that surface can become much hotter than the air surrounding it," he told USA Today. However, air temperature alone isn't a decisive factor. Rather, it's the surface temperature of the sidewalk that matters most.

How Hot Does the Sidewalk Have to Be?

It's estimated that a sidewalk must reach a blistering 158°F to cook an egg throughly. In reality, sidewalk temperatures rarely climb that high, even on the hottest days. Concrete and cement sidewalks aren't efficient conductors of heat due to their light color. On the other hand, a dark asphalt sidewalk will absorb more visible light, allowing the surface to get hotter.

But just having a hot piece of sidewalk isn't enough. "If you've got a road that's at 150 or 155 degrees and you crack an egg onto it, it's going to lower the temperature, and that temperature's not going to heat back up any time soon," said Chef Wylie Dufresne of Stretch Pizza to Smithsonian Magazine. "If you put a couple eggs on a pan, the temperature drops immediately, but recovery is also very quick because you’re on a burner. There’s no recovery on the sidewalk or the road."

What Temperature Does the Egg Need to Reach to Be Cooked?

Egg proteins begin to coagulate at different temperatures. The whites, composed mainly of proteins called ovotransferrin and ovalbumin, start thickening around 142°F, while the yolk proteins condense near 150°F. The myth of frying an egg on the sidewalk persists because people often witness eggs curdling in the heat, rather than actually being cooked through.

How Long Does It Take to Cook the Egg All the Way Through?

Even if the sidewalk manages to reach the requisite temperature, the process isn't instantaneous. When Bill Nye the Science Guy tested how to fry an egg outdoors, he used a griddle on a stove and found that it took 20 minutes to reach a minimum temperature of 130°F to fully cook the egg. But unlike a hot frying pan where heat can be precisely controlled, a sidewalk by itself loses heat rapidly once the egg is cracked open and could take a couple hours, depending on the temperature.

While it's theoretically possible under extreme conditions, frying an egg on the sidewalk remains a feat more of curiosity than culinary practicality. So, the next time the sun beats down and the temperature rises, maybe stick to a grill or stove.

2024-07-09T17:20:12Z dg43tfdfdgfd