by Jennifer Burcke
In my last post, I shared the horror of finding two frozen and cracked eggs waiting for me in our coop on a frigid January morning. I removed their shells and placed them in a bowl in the hopes that they would defrost and be usable in a baking recipe. After they had spent several hours in the refrigerator sans shells, they did in fact thaw and by the end of the day we had chocolate chip cookie bars to eat for a bedtime snack.
In the days that followed, countless chicken keepers shared their methods for combating the bitterly cold weather and frozen water in their coops. I was amazed at the creativity and thankful for all of the great suggestions. I can’t wait to give a few of them a try and share the outcome with you.
By morning, the shells were not gone, but we were making progress. The shell had begun to break down and small portions were completely dissolved. Bubbles were still forming and rising to the surface taking small particles of the disappearing shell with them. The acetic acid in the vinegar was clearly breaking the egg’s calcium carbonate shell into calcium, which was rising to the surface. At the same time, the acid was reacting with the shell to create carbon dioxide in the form of bubbles. We also noticed that the eggs began to float in the vinegar solution. Each time we opened the refrigerator door, they seemed to be closer to floating to the surface of the vinegar.
In minutes, my children were talking to each other about the eggs, the shells, and the miraculous membrane that had survived an environment that the shell could not. Out came the microscope. Soon there was a slide made with a fragment of the dissolving eggshell. Under the microscope, it became clear that what was left of the shell was incredibly porous.
We placed one egg in a clean jar filled with tap water. The second egg was destined for a jar filled with corn syrup. While the first egg was happy to sink in the water, the second refused to be submerged in the thick corn syrup. Instead, it floated on top like an egg-shaped ship lost at sea. I tried to push it down into the syrup, but it was no use. Now it was time to place them both back in the refrigerator for 24 hours.
The next morning, the corn syrup egg had already been transformed. The membrane had given us a lesson in osmosis that was so easy to understand that my 6-year-old grasped it immediately. Because the corn syrup does not contain much moisture, the selectively permeable membrane of the egg had allowed liquid from inside the membrane to exit into the container in order to equalize the pressure. When that happened, the egg was suddenly flabby and deflated, weighing a mere 50 grams. In fact, there was a considerable amount of vinegar now floating on top of the corn syrup in the Mason jar.We could actually pinch the membrane between our fingers and even pick the egg up by the membrane. In contrast, the egg that had spent the evening in water had ballooned up to 91 grams. Its membrane was stretched so tightly that we could no longer press our fingers into it. It felt as if it might burst at any moment.
We held the egg that had been in water up in front of a light to see how translucent it was. We could see the contents of the egg clearly. It was as if we had a three-dimensional cross section of an egg. It was easy to see the yolk, albumen and chalaza. By rotating the egg, we could watch as the contents moved freely. After we finished inspecting the egg in the bright light, we moved on to complete the experiment. We returned the full egg to its water bath. The egg that had spent 24 hours in corn syrup was placed in a clean jar and covered with water. Within a few hours, it had absorbed enough water to be fully formed. When we weighed both eggs the next morning, they each weighed 94 grams.
This experiment reminded me of the marvel of nature that an egg represents. Magic happens out in our chicken coops every day. Now, thanks to our hens and a few store-bought eggs, magic had happened in my farmhouse kitchen. My children learned not just about the egg, but about chemical reactions, osmosis, and permeability while having fun. Here’s another amazing fact: I had as much fun as they did and learned a lot about the anatomy of the egg in the process. Tomorrow morning, when I’m out in the coop delivering morning oatmeal to our hens, I may have to make one change to our morning routine. Instead of addressing them by their names: Hedwig, Amelia, Bertha, Marigold, Abigail, Fawkes and Sally, I may have to call them by a more descriptive moniker. Until I can figure out the appropriate greeting, I’ll guess that, “Good morning, professors” will have to do.
This spring, we’ll be making a few additions to our flock and sharing the experience with you. The chicks are ordered and will be arriving in April. I will be chronicling the life of our new chickens from day-old chicks into laying hens through a recurring series of posts about life in the coop at 1840 Farm. Stay tuned!