Preserving Eggs with Water Glassing

Back in June 2019, Bugman got a wild hair and bought four chicks and a coop for our backyard.

We got our first egg in January 2020.

By May, we were getting four eggs most days.

There’s only two of us in the house, so the eggs really started to accumulate, overflowing the storage space in our fridge. Thanks to our travels in other countries and learning different ways of doing things, we knew that eggs can be safely stored at room temperature, provided they do not get wet and their natural protective coating (called “bloom”) is intact. (We dated each carton and rotated to use the oldest stock first. Also, if it was cold outside and the eggs risked getting condensation when we brought them inside, they went straight into the fridge.)

The photo below shows some eggs we bought, unrefrigerated, at a grocery store in Costa Rica. This took me a long time to trust, since the only rotten-egg experience I’ve ever had was from eggs we bought at a farmer’s market in Iowa, where the sellers clearly did not know what they were doing. I complained about the rotten eggs they sold us, and they gave me a replacement dozen the next week, which were also rotten. Nasty-smelling, runny greenish eggs – YUCK! I will NOT eat green eggs, thankyouverymuch, Dr. Seuss.

We gave some of our excess eggs away to friends and neighbors, but the eggs kept coming. Summer is a bounteous time for backyard egg production, but the shorter day length of winter would mean our chickens would probably slow or stop laying. If we wanted to use our own happy chickens’ eggs throughout the winter, we’d have to find a way to preserve them longer term. There was also the matter of the pandemic, and me feeling the need to store up food in the event that supply-chain problems happened again. I started looking up methods of egg preservation.

I trust university Extension advice on food safety, as they distribute scientifically-rigorous, evidence-based information. But the only non-pickling preservation method I found was to freeze the eggs, which didn’t appeal to me because our freezer was getting filled up with garden vegetables, adding to the volume of fish and fowl Bugman had previously caught and hunted. Plus, the freezing instructions I found said to add sugar or salt to stabilize the egg yolk. I need to reduce my dietary salt for health reasons, and adding sugar meant I wouldn’t be able to use the eggs for any of my typical recipes, so I wasn’t keen on this preservation method.

I tried it anyway without the sugar or salt, breaking and scrambling four eggs into a container, freezing them, and taking them out 4 months later. The result made me a little queasy. The eggs took on a gelatinous, pudding-like texture. They were fine for scrambling, but just overall, not a great egg storage solution for me.

Then I found some information online about “water glassing” as an egg preservation method. There was no Extension-tested method I could find, but it’s apparently time-tested. A friend commented on a post I made about the technique:

I think my grandma talked about WW2 days when eggs were hard to find – never knew when you could “arrange” for some, and said they kept some in the cellar in a big barrel full of “something”, and she would go “fish” for them when needed.

Water glassing involves storing the eggs at cool room temperature in an over-saturated mineral solution — specifically calcium hydroxide, AKA pickling lime. I’m using the term “over-saturated” to mean there is more of the mineral than will dissolve in the water. I assume the mechanism of preservation is that the calcium will deposit on the eggs in the solution and seal up the pores in the egg to keep it from drying out. A “not fresh” egg will float in water, because moisture in the egg will slowly evaporate out through the shell, and air will slowly move in. (The online commentary on water glassing says not to use eggs preserved this way to make hard-boiled eggs without piercing the shell first, because pressure will not otherwise be able to escape, and the eggs will crack/explode when cooked.)

I followed the advice from Carolyn Thomas at homesteadingfamily.com for my water glassing experiment.

  • Make a solution of pickling lime (I bought mine at bulkfoods.com) with 1 ounce by weight pickling lime per 1 quart water. I used distilled water, since I didn’t want to take any chances with our softened-hard tap water that sometimes reeks of chlorine.
  • Put the solution in a food-safe container that has a tight cover. I re-used an emptied and washed 25oz pretzel jar.
  • Choose clean, fresh eggs that don’t have poop, feathers, or nesting material stuck to them. DO NOT WASH THE EGGS before you put them in the solution.

I gently lowered the eggs into the jar using a pasta scoop. I did not want to get that solution on my skin, since a calcium hydroxide solution is quite basic (according to wikipedia, pH of 12.4, about the same pH as household chlorine bleach, which is basic enough to cause chemical burns – don’t get it in your eyes, kids).

I kept adding fresh eggs until the jar was fairly full. Then I screwed the lid on, labeled the jar, and put it in a dark, cool corner of my basement. Note that because of the over-saturation of the solution, there was undissolved pickling lime at the bottom of the container.

Then, I waited.

Round about December, our household egg needs were exceeding the chickens’ output of maybe an egg a day.

I brought the 4-month-old jar of eggs up out of the basement and took off the lid. No funny aroma or anything, but it looked like we’d had some evaporation out of the container, as a solid crust of calcium hydroxide had built up on the surface.

I used the pasta scoop to pull out an egg, and then rinsed it off. I cracked a freshly-laid egg into a dish, and then cracked open the 4-month-old “water glassed” egg. The main difference I could see was that the egg white was runnier on the older egg (at left) than the fresh egg (at right).

I’ve used these water-glassed eggs for making fried eggs, scrambled eggs, and baked goods, including separating the egg whites and beating them to stiff peaks, and everything has worked out just fine.

I’d say the only downfall I’ve come across with this method is that the membrane around the egg yolk seems more fragile, so it’s harder to crack an egg without breaking the yolk.

We’ve not run into any food safety problems with this method that we’re aware of. Still, I would feel more comfortable recommending it if I knew it was scientifically tested. If anyone knows of any bona fide scientific food safety references about water glassing, please send them my way. I’m also curious about whether this preservation method changes the pH of the egg.

Copyright 2021 by Katie Bradshaw

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