Eggs are compact, high in protein, and nutrient dense. This makes them an integral part of a healthy diet. The downside is that they tend to have a short shelf-life unless you take steps to prevent spoilage. One of the easiest and effective ways that I have discovered is to use mineral oil. In this article I will teach you how to preserve eggs with mineral oil. When eggs are stored this way, they can last a long time even without refrigeration!
How do you preserve eggs with mineral oil?
- Collect, wash, and dry a dozen fresh eggs.
- Warm up 1 tablespoon of mineral oil in the microwave for 10 seconds.
- Let the oil cool.
- Wear gloves and cover each egg completely with mineral oil.
- Place the eggs in an egg carton with the small ends down.
Those are the basic steps for preserving eggs with mineral oil, but how long will they last? Also, are there other things you can do to prolong their shelf life? Continue reading to find out!
Why preserve eggs with mineral oil?
While you can use powdered eggs or egg substitutes, there’s something so satisfying about enjoying a hot plate of fried eggs, an egg sandwich, or hardboiled eggs by a campfire. Unfortunately, you can’t make any of those with powdered eggs.
Real eggs are invaluable because they can refuel your body, fill up your belly, and replenish your nutrient stores without taking up a lot of your storage space. If you don’t have your own healthy flock of egg layers, then the biggest issue with eggs is that they don’t last long without refrigeration. The last thing that you need is for a forgotten egg to explode and destroy your food stash.
This is where mineral oil preservation comes in. It is an egg preservation method that has been used through the ages. Additionally, mineral oil is cheap, easy to acquire, simple to store, and a little goes a long way. A nice bonus is that it also has other survival uses.
Quick & Simple Egg Science
I think that it is so important to know why something works rather than just “that something works.” This is especially true for anything that you plan on ingesting. I hope that these egg facts will help you to select the best eggs to preserve. Additionally, it is important to identify a compromised egg so that you can avoid it. I will cover more important tips in this section. Let’s keep going!
- Eggs that are freshly laid can last several weeks to a few months outside or on your counter(depending on the temperature). This is thanks to “bloom” which is a protective layer that helps regulate oxygen exchange and prevent bacterial infections. Did you know that fresh eggs don’t need to be refrigerated? I have left fresh, unwashed eggs on my counter for up to 4 months and they were delicious.
- Store bought eggs get scrubbed and bleached. This process removes dirt, feces, and bloom. These eggs must be refrigerated because the protective bloom has been removed. They can potentially last a couple of days on your counter, but not much longer.
- Keep in mind that store bought eggs may have been laid more than 60 days ago. There is no way to know how old those eggs are especially since there is no law that mandates farmers or stores to disclose when your eggs were laid.
- The older an egg is, the more likely it is to float in a bowl of water. Oxygen slowly seeps in through the shell. This increases the size of the air cell that is located at the fat end of the egg. It also happens when moisture evaporates from the egg and creates more room for air and bacteria.
How to preserve eggs with mineral oil
This egg-preserving method is safe, quick, simple and has been used for decades.
You need:
- Eggs (fresh or store bought)
- Mineral oil -you can find it at farm supply stores, grocery stores, drug stores, or online.
- Nitrile or rubber gloves
- Bright flashlight or egg candler
- Egg carton (a plastic carton is best for long term storage and protection)
- Small pot or microwave safe bowl
- Measuring cup
Step 1- Float Test
I always float test my eggs even though they come from my own flock of hens and I know how old they are. It’s just good food handling.
Fill a pot or bowl with enough cool water to cover two eggs stacked on top of each other (you won’t actually be stacking the eggs. This is just for depth). Carefully place the eggs in the water one at a time.
If the egg stays on the bottom, it’s fresh and ready to preserve!
If the egg starts to rise to the top, but doesn’t break the surface, it’s not completely fresh, but can still preserve it.
When the egg floats to the top and bobs at the surface, this means that it has a large air cell and is old and not fresh enough to preserve.
Once you have have tested your eggs, dump the water out and dry the container.
How to tell an egg is fresh – Delia’s How to Cook – BBC Food
Step 2- Prepare the eggs
Wash, dry, and carefully place your eggs on a towel or in a container. It’s not yet time to put them in the carton. Once your hands are covered in oil, it will be impossible to remove them from the carton. If you are using fresh eggs, don’t rub or scrub too hard. That will remove the bloom. Also, remember that eggs are breakable. While you can still preserve eggs once the bloom is removed, it is much better if it is still intact.
Step 3- Candle the eggs
The point of “candling the eggs” is to check for air cell size, cracks, and embryonic development.
In a dark room, turn on your flashlight or candler and hold the large end of the egg against it. Now look for three distinct parts.
- A little pocket of air by the fat end of the egg
- A floating dark circle (this is the yolk)
- The gooey white part around the yolk
If any of these three parts are missing then the egg is not suitable enough to preserve.
An unfertilized egg (or a fertilized egg that hasn’t developed) will appear mostly clear with a darker floating yolk. You should be able to carefully spin the egg and watch the yolk move freely inside. This is a winner!
If you find dark spiderweb-like strings, that is an early stage embryo. It is not good for preservation, but you can still eat it.
Cracks will look like bullet holes in glass or lightening strikes. These eggs are not good for preservation and you should not eat them.
Egg Candling From Day 1 To 21/ Egg Hatching
Step 4- Measure the oil
Measure one tablespoon of mineral oil per dozen eggs. Since I preserve four dozen eggs at a time, I usually use about 1/4 of a cup of mineral oil (four tablespoons). Put the mineral oil in a pan or bowl.
Now warm the mineral oil for about 10 seconds in the microwave or a few minutes on the stove. Allow the oil to cool slightly before you begin the preservation process (to avoid burns.)
Step 5- Use protection
Glove up! Always perform “safe preservation.” Mineral oil has a few minor drawbacks, but your gloves will prevent it from affecting you. Putting on your gloves will also give your oil enough time to cool down.
Step 6- Rub them down
Poke your fingers in the warm oil and rub it around your gloves. Once your gloves are coated in oil, gently pick up an egg and roll it around in your hands. Be sure to cover every inch or each egg in oil. Don’t worry about putting it on too thick. Slather away because the whole point is to seal it up to prevent oxygen and bacteria from entering.
Step 7- Store them bottoms up
Once the egg is completely covered in oil, place it in the egg carton fat side up.
You did it! The process is complete. Find a cool, dry, and dark location to safely store your eggs.
EGGcellent food storage
Do you need to flip eggs preserved in mineral oil?
Yes. It is best to flip eggs that are preserved in mineral oil about once a month. This will help to preserve the yolks and prevent them from sticking and settling. Now set an alarm or pencil in an egg-flip date in your calendrer.
What does science have to say about oil-preserved eggs?
I just happen to have a link to some egg preserving science right here. The gist of the study is that oil preservation works and it is safe.
This specific experiment proved that oil-preserved eggs that were kept at 77 degrees Fahrenheit maintained a higher internal quality and decreased moisture evaporation over a five week period than non-coated eggs.
Remember our egg facts that talked about evaporation and the air cell? According to the study on the NCBI website, at the 5-week-point, the oil-preserved eggs lost less than 0.8% of their weight via evaporation. The non-coated eggs lost 7.26%. That means that the non-coated eggs gained more air and lost more moisture. And guess what more air indicates? Bacteria!
How long will mineral oil-preserved eggs last?
Eggs that are preserved with mineral oil can last anywhere from six months to a year. This depends on storage conditions and the freshness of the eggs when they are preserved.
The duration of study I liked above was only five weeks and the eggs were kept at a pretty high temperature (the temperature of an average kitchen counter.) Five weeks is still a substantial amount of time to keep eggs unrefrigerated.
I wish that the study would have gone on to test how long the eggs would remain safely edible at that temperature. Sadly, that’s not the case and the study ended. If you don’t mind a little educated speculation, then some math could help us. The study went for five weeks and they only noted a .8% weight loss, so it’s probably safe to say that a preserved egg might only lose 1.6% at 10 weeks and 3.2% by twenty weeks.
If you lower the temperature, then you could significantly extend that time.
We can also look to experienced homesteaders, survivalists, and preppers for answers. My eggs lasted about nine months in the fridge. The eggs didn’t go bad at that point, we just ate them all. They retained their correct shape and weight, didn’t have any noticeable taste or texture changes, and they were delicious! However, I did notice that they weren’t the best for baking.
This lady tested year old oil-preserved eggs
She discovered that even after a year, the oil-preserved eggs were quite tasty. She stored them in the fridge and observed some minor effects, but overall, they were in good shape. Proper temperature is the key to keeping these eggs edible. While any cool, dry, dark location will work, the fridge seems to be the best option.
Can you freeze these eggs?
I don’t know of a single egg-preserver who freezes their eggs after oil preservation (it’s a bit redundant.) I have frozen eggs before, but it was always after they were peeled. Since liquid expands when frozen, it stands to reason that freezing an oil-preserved egg in its shell would result in explosions and a massive mess.
I personally wouldn’t freeze oil-preserved eggs. If you discover a way to freeze mineral oil-preserved eggs in their shell, please comment below because I would love to hear about your method.
Can you use coconut oil or other oils to preserve eggs?
Most oils will work, but coconut and many other types of oils will eventually go rancid. That is why it is best to preserve your eggs with mineral oil.
Using eggs that are preserved in mineral oil
These eggs won’t work well for baking or anything that needs fluffy, whisked, egg whites. Otherwise, they work well for everything else. Make sure that you wash them well before you use them.
Warnings:
Mineral oil is a refined petroleum product. It is primarily used as a laxative and you can find it in stores near stomach medicines. If you ingest large quantities of this stuff, you will need to make frequent bathroom runs so don’t chug it.
Mineral oil can disrupt or change estrogen levels in women, so always perform mineral oil egg preservation with gloves on.
Additionally, it’s important to make sure that you don’t burn yourself after heating the mineral oil. Oil based burns are the worst and the oil can heat extremely well in a short period of time.
Conclusion
I have been preserving eggs for many years and the suggestion of only using warm 24 hour old eggs is a bit unrealistic and silly for most people. Make sure that you use common sense and always use proper food handling techniques. If you follow these steps, choose healthy, undamaged eggs, and pay close attention to temperatures and storage methods then even store-bought eggs can be preserved in mineral oil.
Have you ever preserved eggs? What are your tips, tricks, and storage methods? Comment below to share!
See you soon.
