6 ways to preserve eggs

In this brief guide, we are going to answer the question “6 ways to preserve eggs” and discuss 6 ways to preserve eggs along with the benefits and implications of each method.

6 ways to preserve eggs

A large prospective cohort study of >0.5 million people from China (Kadoorie Biobank Study) reported that intake of 1 egg/d was associated with 11% lower risk of cardiovascular disease (1).

6 common ways to preserve eggs are:

  1. Freezing
  2. Freeze-drying
  3. Dehydrating
  4. Mineral oil method
  5. Water-glassing
  6. Pickling

How to preserve eggs by freezing

Freezing is used to preserve both raw and cooked eggs. However, eggs must not be frozen in their shells (3). Frozen eggs can be thawed in a container in the refrigerator overnight. Thawed eggs must not be refrozen (4).

To freeze raw scrambled eggs:

  • Lightly scramble the eggs.
  • Add sugar or salt. If salt or sugar is not added, the egg yolks will thicken during freezing.
  • Pour into muffin trays or ice cube trays and freeze them for a few hours.
  • Transfer into ziplock bags, label and place them back in the freezer.

To freeze cooked scrambled eggs:

  • Cook scrambled eggs and allow them to cool down to room temperature.
  • Wrap the eggs in plastic wrap and remove all air.
  • Place the plastic wrap inside a ziplock bag or cover it with foil.
  • Label and place it in the freezer.
  • Cooked scrambled, frozen eggs must be used within 1 year.

Freezing separated eggs: Egg whites and yolks can be frozen separately.

To freeze egg whites and yolks separately:

  • Separate eggs into whites and yolks.
  • Lightly stir the egg whites and yolks separately. For egg yolks, add sugar or salt to prevent thickening.
  • Freeze them in an ice cube or muffin tray.
  • Transfer into ziplock bags, label and place them back in the freezer.

More about freezing eggs can be found here.

How to preserve eggs by freeze-drying

Freeze-drying (lyophilization) is a drying process in which the solvent (usually water) and/or the suspension medium is crystallized at a low temperature and thereafter sublimated from the solid state directly into the vapor phase (2).

Freezing allows the preservation of the proteins and nutrients in eggs for a long period. The main drawback of freeze-drying is that it requires a freeze dryer.

Both cooked and raw scrambled eggs can be freeze-dried. Freeze-drying, including pre-crystallization and rapid freezing, allows the functional properties of egg yolk to be preserved. Since full contact rapid freezing makes it possible without liquid nitrogen, freeze-dried egg yolk can be produced even at marketable costs. Once the water is removed, the product vials are sealed under vacuum or an inert gas space (i.e. N2, Ar) and can be stored over extended periods of time at the designated storage conditions until its intended use (2). Freeze-drying preserves 97℅ of the nutritional value in eggs for about 25 years. To obtain the best shelf-life from freeze-dried eggs, they must be stored in an airtight container in a cool and dark place. It is also recommended to add an oxygen absorber.

Freeze-dried eggs can be used as a substitute for freshly cracked eggs in baking, scrambling and even as an egg wash.

How to preserve eggs by dehydrating

Eggs can be scrambled or hard boiled and then dehydrated using an oven or a food dehydrator. After dehydration, eggs can be ground to a powder in a food processor. Dehydrated and powdered eggs can be stored in an airtight container or vacuum-sealed.

The phenomenon underlying this process is a complex problem involving simultaneous mass and energy transport in a hygroscopic, shrinking system. Air-drying offers dehydrated products with their shelf life being extended by a year, but the quality of a conventionally-dried product is usually drastically reduced compared to that of the original foodstuff (2).

Home-made dehydrated eggs can last for about a year. If frozen, dehydrated eggs may last for about 25 years, according to the USDA food safety guidelines for egg products. (Wiki link)

How to preserve eggs by using mineral oil

During storage, the loss of moisture and carbon dioxide via the shell pores causes quality changes in albumen and yolk as well as weight loss of eggs. Therefore, a protective barrier against transfer of carbon dioxide and moisture is necessary to preserve the egg quality (5).

Eggs coated with mineral oil will preserve for about 5 weeks3 months at room temperature and up to 10 weeks1 year when refrigerated. The advantage of the mineral oil method is that it can be used to preserve whole raw eggs (5).

To preserve eggs will mineral oil:

  • Clean and dry whole raw eggs.
  • Warm-up mineral oil.
  • Rub mineral oil over the whole eggs.
  • Place the mineral oil-coated eggs in a dry carton with the small end down.
  • Gently flip the egg carton either monthly or weekly. This is done to keep the yolks intact.

How to preserve eggs by water-glassing

Water-glassing is a unique method used to preserve eggs. Water-glassing preserves whole, raw eggs for 3 to 6 12 to 18 months (6). 

The disadvantage of water-glassing is that it can be done only on farm-fresh, unwashed eggs with the bloom intact. Eggs bought from supermarkets and groceries cannot be preserved by water-glassing since they have already been washed and bleached. 

Water-glassing is a quick and efficient method of preservation requiring only farm fresh eggs, distilled or spring water, pickling lime and a food grade bucket or a container. During water-glassing, the eggs are immersed in a mixture of distilled water and lime and kept in a cold dark place until needed. 

Eggs removed from the mixture must be washed and kept in a refrigerator if they are not immediately used.

A complete method for water-glassing can be found here.

How to preserve eggs by pickling

Pickling is a traditional method of food preservation applied to fruits, vegetables, and foods of animal origin such as meats and eggs. Due to the composition, size, and physicochemical properties of eggs (egg yolks have a high fat and protein content of 32.5 and 17.5%, respectively), pickled eggs pose unique challenges to quick and complete acidification and, therefore, proper preservation. Acidification itself leads to textural changes in the pickled egg, exhibited as a toughening of the egg as a whole. These rheological changes are expected with hard-cooked pickled eggs and do not seem to be influenced by the amount of acid or by the thermal treatment applied to the pickled egg (7).

Hard-boiled eggs can be preserved by pickling. Pickling is done by submerging hard-boiled, peeled eggs in a solution of vinegar, sugar and a choice of spices. Hard-boiled pickled eggs will last for about 9-123 – 4 months when refrigerated in an air-tight jar (7).

4 recipes for pickling eggs can be found here.

Other FAQs about Eggs that you may be interested in.

Are Egg Whites Vegetarian?

What can you substitute for eggs?

Can you get sick from eating raw eggs?

Conclusion 

In this brief guide, we answered the question “6 ways to preserve eggs”. We discussed 6 methods of egg preservation and looked at the benefits and implications of each method.

If you have any questions or comments, please let us know.

References

  1. Dehghan, Mahshid, et al. Association of egg intake with blood lipids, cardiovascular disease, and mortality in 177,000 people in 50 countries. Am j clin nutr, 2020, 11, 795-803.
  2. Ciurzynska, Agnieszka, and Andrzej Lenart. Freeze-drying-application in food processing and biotechnology-a review. Polish J Food Nutr Sci, 2011, 61.
  3. If shell eggs freeze accidentally, are they safe? Ask USDA. 2019.
  4. Haley-Hadley, C. Freezing eggs to keep them longer. 2022. University of Arkansas.
  5. Torrico, Damir D., et al. Mineral Oil–Chitosan Emulsion Coatings Affect Quality and Shelf-Life of Coated Eggs during Refrigerated and Room Temperature Storage. J Food Sci, 2011, 76, S262-S268.
  6. Alder, B. Preserving Eggs for the Home. 1917. Utah State University.
  7. Usaga, Jessie, et al. Pickling Eggs. Egg Innovations and Strategies for Improvements. Academic Press, 2017. 405-413.