Outside in
After scientists came up with a way to partially unboil an egg, seven years ago, researchers have now cooked up a solution to a superficially similar challenge: how to boil an egg so that the yolk winds up on the outside of the inside.
The partial unboiling was revealed in the journal ChemBioChem in 2015. The scientists used a centrifuge-like device to spin a clump of folded (or, depending on one鈥檚 point of view, misfolded) proteins. This proved to be a quick, inexpensive way to get some of those proteins to re-fold themselves 鈥� to revert their boiled molecular shapes back into earlier, pre-boiling configurations.
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Rather different is the way Hajime Hatta, Ayami Nakamoto and Yasumi Horimoto say they solved a more-than-two-centuries-old egg-inversal mystery. They reveal their method in a paper titled .
The study explains that the cookbook includes 103 egg recipes, of which only the reversed boiled egg has never been reproduced. 鈥淭he key to solving the mystery,鈥� write the researchers, 鈥渓ay in the idea that the eggs used for cooking in such an old period could be mostly fertilized eggs. We finally reproduced the reversed boiled egg by using fertilized eggs incubated for three days at 38 degrees C.鈥�
The secret, they say, is that in unfertilised eggs, the yolk is thick and sticky, while the egg white is runny. But with a fertilised egg, the reverse is true: the yolk is watery and runny, while the white is thick and sticky. So the yolk can ooze outside the confines of the white.
Up with eggs
Cultural historian Alison Vincent, meanwhile, pursued her own, no-cooking-involved vision of what can, but maybe should not, be done with eggs, preparing a partial history of when, why and how eggs have been tossed at politicians. In a paper presented at the Dublin Gastronomy Symposium in 2020, she says: 鈥淧ractically eggs are easy to acquire, in that they are relatively cheap and readily available, easy to conceal and easy to transport, taking care that they do not break before required.鈥�
Vincent took care that her paper not be overly egg-centric. The reader is advised that 鈥渁nother not uncommon projectile used in similar circumstances is the pie鈥�.
The egg man
Eggs have gone largely unmentioned in the mudslings and rhetorical arrows about Brexitannia being potentially cut off from reliable access to foreign food sources. It is cheering to learn how hard Hugh Cott worked to solve similar worries in the mid-20th century. A zoologist at the University of Cambridge, Cott oversaw a project to sample the many kinds of bird eggs laid in Britain (and a few laid elsewhere). The goal: to ascertain which would be edible, or at least palatable, should the worse come to the worst in a time of dwindling food supplies.
Cott published a series of thick reports in the Proceedings of the Zoological Society of London. The titles are a fair summary, from to .
They make for delicious reading. For the egg panel, 鈥渟amples were tested in the form of a scramble, prepared over a steam-bath, without any addition of fat or condiment鈥�. Each taster assessed each sample on a scale dropping from 鈥渋deal鈥� down to 鈥渞epulsive and inedible鈥�. The paper concludes with a list of the different egg types 鈥渋n descending order of acceptability鈥�.
At the top was chicken, then emu, coot and black-backed gull. The eggs of last resort, as rated by official British egg-tasting persons: green woodpecker, Verreaux鈥檚 eagle owl, wren, speckled mousebird and, dead last, black tit.
Tadpole tastings
Cott was also addressing the question of why the most conspicuous eggs taste terrible to whatever might want to eat them. Ditto the kinds of birds that were strikingly easy for predators to spot. Phrased starkly: Why have gaudy critters not been long ago gobbled up and become extinct? The answer: the flashy ones usually taste terrible.
Enamoured of tadpoles, and inspired by Cott鈥檚 feasts, biologist Richard Wassersug loosed a panel of graduate students on the issue. His study, , published in the journal The American Naturalist in 1971, describes what happened:
鈥淭he tasters were asked to rate the palatability of each tadpole鈥檚 skin, tail, and body on a 1 to 5 scale鈥� A tadpole was rinsed in fresh water. The taster placed the tadpole into his or her mouth, and held it for 10-20 seconds without biting into it. Then the taster bit into the tail, breaking the skin and chewed lightly for 10-20 seconds. For the last 10-20 seconds the taster bit firmly and fully into the body of the tadpole. The participants were directed not to swallow the tadpoles but to spit them out and to rinse their mouths out at least twice with fresh water before proceeding.鈥�
The results pretty much confirmed the idea that the more conspicuous the tadpole, the less palatable it is likely to be.
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