Since at least 1899, Americans have speculated about frying an egg on a summer sidewalk. Can it be done?
Short answer – no. Long answer – it depends. Ah! The joy of “it depends.”
You can’t believe YouTube! You didn’t really think you could, did you? You’ll have to try for yourself.
Do this at home, if you don’t mind making a mess. First – set the parameters of your experiment. How cooked must your egg become?
When you cook an egg, the heat transfers energy to the molecules, causing the proteins to unravel. After a few minutes, the strings of proteins weave and bind together, and most of the water evaporates.
Yolk proteins begin to condense near 150 degrees Fahrenheit, while the albumen proteins ovotransferrin and ovalbumin thicken near 142 and 184 degrees, respectively. smithsonianmag.com
Let’s say you like runny yolks. Maybe softly-set egg whites too. So aim for… oh, let’s round it off and say, 140 degrees F.
I know from my wildland fire fighter training that dry grass baking in the sun can routinely reach 100 degrees F. A record for the highest official temperature on Earth comes from Death Valley USA: 134.1 degrees F (56.7 °C) That’s the temperature of the air, not a solid soaking up photons.
People quibble over that record, and you may not want to take your egg to Death Valley, but this seems promising.
It’s not just temperature that matters, it’s heat transfer. Ever bake a cake? Did you tap the cake’s top to judge if it’s done? Would you tap the pan? The difference is heat transfer rates.
So how about the sidewalk? Concrete isn’t the best material to transfer heat to a food item, which is why we don’t have a lot of concrete fry pans.
Asphalt would be better, “smoother and tighter, and also going to be hotter and hold its heat better… 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 [at that spot], and that temperature’s not going to heat back up anytime soon.”
My home town in upstate New York, USA, has sidewalks made of slabs of black slate. Better than concrete for sure, but I don’t know how it compares to asphalt.
There are lots of ways to cook with solar ovens, and mirrors, aluminum foil, and magnifying glasses can help too. Is any such equipment allowed for your experiment?
I tell you what. I’m going to sit in the shade with a cold drink. Let me know how your experiment turns out.
Thanks to smithsonianmag.com for their article.