Friday, 19 September 2014

Limewater eggs

No matter what else most of us have in our kitchen, most of us probably have eggs. They are a staple source of protein the world over, and a vital ingredient in dishes from almost every culture. Yet chickens slow down their egg production in the winter, and in the summer you get a surfeit of eggs, so a way to preserve them would be immensely helpful.

One way, of course, is to separate the eggs and yolks and keep them in small plastic containers in the freezer. Freezers need electricity, however, and we might not always have that in emergencies – my relatives in Missouri have experienced periodic power outages for up to two weeks at a time, and friends in Louisiana experienced a lot more than that in hurricanes. When the Irish economy tanked a few years ago and the country went bankrupt, we weren’t sure whether the power would stay on, and in other countries they haven’t. In short, everyone should be prepared to cope without electricity for a while, just in case. We need some other way to preserve eggs, and thankfully there is a nearly forgotten method that we could revive.

The answer is to preserve eggs in limewater, a simple mix of tap water and lime powder; I’ve done this with our eggs, and they lasted for months and came out perfectly fresh. “Lime” here means neither the citrus fruit nor the tree, but refers to a white powder derived from limestone. For at least 7,000 years humans burned limestone in kilns to create quicklime, and hydrated that to create lime powder. For hundreds of years until the mid-20th century, lime supported a vast and vital network of village industry -- quarries to mine the limestone, carts and barges to transport it, and specialists to monitor the burning. In the late 1700s, according to one survey, County Cork alone was said to contain an amazing 23,000 kilns, or one every 80 acres.

The Irish used lime to spread over fields, its alkalinity “sweetening” the acidic soil and increasing crop production – as much as fourfold, according to some accounts. Lime was used as a cement as far back as the ancient Sumerians, and Romans used it to create a waterproof better, in some ways, than what we use today. Lime also forms the basis of whitewash, used for centuries to protect and brighten structures, fences, vehicles and even trees, without the alarming and unpronounceable stew of toxic ingredients in many modern paints. Farmers rubbed it on their livestock’s feet as an antiseptic, or painted it onto fruit trees to prevent fungal diseases. Some mixed a bit of lime into well-water to disinfect it, or to preserve eggs for months without spoiling. Tanners used it to remove hair from hides, gardeners to repel slugs and snails, printers to bleach paper. It was, in short, pretty useful stuff, and still is.

To keep eggs in limewater, I simply mixed equal parts of lime and water in a mayonnaise jar, shook it, and delicately added eggs – they kept fresh for several months. A more traditional recipe, however, was to mix one pound of lime per one gallon of boiling water – that works out for us to be about 84 grams of lime for a 700-ml jar. Then let the mixture cool and pour it over the eggs. Still other recipes mixed the lime with saltpeter and even borax, but I would not try those until I had confirmed their safety.

Finally, one more approach to preserving eggs without electricity, which I have not tried myself, involved using sodium silicate or glass-water. One popular recipe from a century ago recommended dissolving sodium silicate in boiling water, to about the consistency of a syrup (or about 1 part of the silicate to 3 parts water). The eggs -- as fresh as possible, and thoroughly clean -- should be immersed in the solution in such manner that every part of each egg is covered with the liquid, then removed and let dry. If the solution is kept near the boiling temperature, the preservative effect was said to be much more certain and to last longer.

The eggs that were preserved in this way were said to have a slight odour to them, but nothing particularly foul, and I never noticed much of a difference. Both approaches keep the nutrition of the eggs, and keep out any of the germs that would cause illness, allowing people to have a store of protein ready for any emergency.


Sarah R said...

Thanks for an interesting post. I'm guessing that these methods all work because you're excluding oxygen from the egg? Or is there a chemical reaction of some sort? Is glass water the same thing as isinglass? My grandmother used to store eggs in that, but I don't really know what it is. I'm assuming that you're talking about whole, raw eggs, and I'm guessing they should be wiped but not washed. Is that right?

Juliana said...

This is may be a dumb question, but do you leave the eggs in the shell when you do this? I would think that the lime would eat the shell away.

Brian Kaller said...


Thanks, and good questions. I can't speak with any scientific authority why it works, but I guessed the same as you -- it excludes the oxygen and suspends the egg in a solution caustic enough to kill any microorganisms while not being toxic to humans.

Glass water is indeed the same as isinglass. I'd like to try it sometime, although it's surprisingly difficult to come by in Ireland. Yes, I wiped the eggs clean before placing them in the limewater, although I don't know whether a more thorough washing would have done any harm.

Juliana, I put the eggs in raw and in the shell, and the limewater does no harm. It's made from limestone, which is similar to the composition of eggshells anyway.

Dan said...

I'm a bit puzzled... why preserve the eggs (in situations without electricity or freezer) when the hens are laying eggs daily?

Brian Kaller said...


In case your hens stop laying altogether during the winter. Or you have to move somewhere away from your chickens. Or you have a lot of friends coming over. Or your hens get eaten by foxes. Or whatever; it can't hurt to be prepared.