The Eggstraordinary Fortress

Summary

It began, as many thought exercises do, with a discussion in the kitchen. My wife and I were debating whether a cooked egg was still safe to eat after spending the night on the kitchen counter. I am certainly not the type to throw away food lightly at the lightest hint of an issue. Confidently, I told her the egg would be fine. After all, eggshells are made of calcium carbonate, solid, sealed, and, in my mind, impenetrable to any contaminants. It turned out to be one of those “smart dumb” moments. By the end of this journey, I would learn how spectacularly wrong I was, and how remarkable life is at engineering security. A humble egg that is a marvel of security engineering. My background is in sterile large molecule manufacturing within biotech, the kind of work where even a single microscopic breach within thousands of gaskets and kilometres of stainless steel can trigger an investigation lasting months or even years. I have spent much of my career designing systems to keep contaminants out and tracing them when they find a way in. Yet for all the effort, precision, and technology we pour into security, after this curiosity-driven journey, I came to the conclusion that nothing I’ve seen in biotech compares to what nature achieves effortlessly inside an egg. To keep things simple, I focused on one scenario: an unfertilised, intact chicken egg. As I went down the rabbit hole of Eggsecurity, I discovered that the egg is an astonishingly well-designed fortress. Before diving into the details, it is worth noting just how nutrient rich an egg truly is. It is so abundant in life-sustaining material that even today, many biopharmaceutical products are made using eggs. To a bacterium, reaching the egg yolk must be like winning the lottery. The yolk’s purpose, after all, is to nourish life itself. My first question was simple: are eggshells porous? It turns out they are not only porous, but contain thousands of microscopic openings. The average pore size is in the single-dig...