by Fangfei Shen
One day, I plopped a small pot of water with a single egg onto a stove. I stuck into the water the thin pointed metal rod of an old meat thermometer, connected by braided wire to a grimy digital temperature display that sat on the nearby counter. I fired up the stove, pulled up a kitchen stool and sat there watching. Then I turned the stove off. After a few minutes, I turned the stove back on. For the next half hour, I repeated this process.
Not unexpectedly, several hall mates asked me what I was doing, because the setup seemed a bit off from “just cooking.” I would reply that I was on an eggventure of eggsperimentation, eliciting groans from the hall mates at my puns. Just what was I, ahem, eggsploring? I was exploring the science of cooking an egg.
I don’t claim to be in love with eggs. While I may enjoy the occasional egg, whether scrambled or hardboiled, or in a quiche, omelet, or even custard, very rarely do I crave unborn fowl, nor do I normally try to devise exciting new ways in which I can consume them. However, a nagging desire to experiment with eggs overtook me after reading a Discover article by Patricia Gadsby called “Cooking for Eggheads,” which reports on some Parisian research in molecular gastronomy.
Gadsby describes molecular gastronomy well: it “aims to apply the piercing clarity of science to the culinary arts.” It’s not the science of food, but rather the science of cooking the food and the appreciation thereof. As the title may suggest, “Cooking for Eggheads” focuses on cooking eggs as a classic example of molecular gastronomy in action, and the egg-cooking process fascinated me.
What is there to cooking an egg? In conventional cooking, it’s all about how long the egg is heated. Boiling is a good example. Whether you get a hard-boiled, soft-boiled, or inedible egg depends on the boiling time. In molecular gastronomy, however, temperature dictates how an egg is cooked.
The fundamental difference between a raw egg and a fully-cooked egg and everything in between is how denatured the egg proteins are, and heat is one way to denature a protein. Denatured proteins clump together more easily, giving a cooked egg its solidity. The different proteins in an egg denature at different points between 61°C and 85°C (for those used to the Fahrenheit scale, that’s about 142°F and 185°F), so if an egg is cooked somewhere in that range, what will happen? Partial denaturation, of course, which makes for an interesting-looking egg.
Gadsby described the appearances of a 64°C, a 65°C, and then a 67°C egg cooked in its shell, but words on a page were not enough for me; I wanted to see one of those eggs with my own eyes. At that point, I had only seen 100°C (212°F) eggs, also known as eggs boiled in water. I became fascinated with the idea and decided it was time for me to start experimenting, which brings us back to the scene in the kitchen.
In Gadsby’s article, eggs were baked at specific temperatures in a lab oven, but at the time of this writing, I have yet to gain access to any oven meant to cook in the 61°C to 85°C range. Instead, I improvised and used manual feedback of heated water on a stove, moderating the temperature by turning the flame on and off for thirty minutes while watching the temperature with the only thermometer I could find in the kitchen, that grime-covered meat thermometer of questionable accuracy. (The thirty minutes benchmark was an arbitrary, unscientific decision; I wanted to make sure the egg would be heated thoroughly, and thirty minutes happened to be an adequate amount of time for that.) Needless to say, my method of temperature moderation was hardly precise and rather labor-intensive, but it worked well enough.
The first time I did this, I was merely interested in seeing the physical manifestation of an egg cooked according to the methods of molecular gastronomy. I “boiled” an egg at around 90°C, having accidentally overshot a lower temperature. Ah well. The egg, with its firm white and a bright-yellow solid yolk, turned out beautiful—but also very much hardboiled. This wasn’t unexpected; by 85°C, all egg proteins should have coagulated, so an egg cooked at approximately 90°C was understandably solid. I ate the egg. It tasted like any other hard-boiled egg. It was time to try again.
This time, I made sure not to let the temperature climb too high, cooking the egg at around 70°C (an arbitrary temperature). The results were starkly different from the last. I had never seen the likes of such an egg before; the yolk was a solid orange-yellow squishy ball, and the white had the consistency of silken tofu. The egg matched Gadsby’s description of the 67°C egg. Unfortunately, I didn’t have the guts to eat it. Despite the white egg white and the set yolk (and the knowledge that salmonella died at 60°C), it looked too raw for comfort. I gave it to a friend instead. This time, I was merely satisfied with seeing the egg. A week later, I saw the same friend implementing my method of egg-cooking to cook her own 67°C eggs. It must have been tasty, I thought, but I still had no desire to eat any less-than-solid egg.
A year later, curiosity overtook me again. I had seen what those eggs look like, but what about their taste? Suddenly, I realized the silliness of embarking on a culinary adventure of molecular gastronomy where tasting the edible result was not on the adventure’s menu. Molecular gastronomy does not exist to use food to produce cool science. It exists to use cool science to produce food to eat. I gave in to my curiosity and created the same setup once more, plopping down a pot of water on the same stove with an egg and the same dirty old meat thermometer, cooking the egg at around what the thermometer told me to be 67°C.
After the egg was done “cooking,” I cracked the egg rather than unshelling it, and the insides gushed out. The white again resembled silken tofu, but this time the yolk was only slightly set, looking like an immaculate and perfect flattened orange sphere (or as perfect as a flattened sphere could look). The egg looked similar to Gadsby’s description of a 65°C egg.
Last time, I chickened out eating my molecular gastronomy-inspired egg. This time, I didn’t want to chicken out again. With some hesitation, I lowered a spoon into the white, which parted more easily than even custard, and scooped a small sampling up to my mouth. “I feel so weird eating this egg,” I said, before eating the white. The flavor wasn’t bad at all, reminiscent of egg drop soup, and the texture was more delicate and watery than the white of a boiled egg. Next I turned my spoon to the yolk and split it into quarters. The yolk neatly pinched into two, and then into four. I placed a quarter of the yolk into my mouth and squished it between my tongue and the roof of my mouth and let the yolk run over my taste buds. I sat there for a moment, simply musing over what was going on in my mouth. The experience was strange; the taste was similar to that of any other egg yolk, whether runny or firm, but the texture was a world of its own. This 67°C egg yolk was smooth and gooey, and it enveloped the roof of my mouth and tongue in what felt like a thin film of yolk, as if the yolk was trying to lock its flavor into my taste buds.
Well, thank you molecular gastronomy. I’ll make that egg again, and I’ll eat it too.
Gadsby, Patricia. “Cooking For Eggheads.” Discover. Feb. 2006: 38. Print.
Fangfei Shen, Class of 2011, graduated as a double major in Physics and Writing, and is continuing her studies in the MIT Graduate Program in Science Writing. Her favorite physical constant is h-bar, and she likes far too many foods to choose a favorite. Special thanks to Dr. Karen Boiko, the instructor for the class Food for Thought for which this essay was written.