Tips

The Ultimate Guide to Egg Preservation: Keep Them Fresh for Months on End

Dr. Tan Vu, a renowned scientist from Hanoi University of Science and Technology, conducted an intriguing experiment on egg preservation. He compared the effectiveness of simply refrigerating unwashed eggs versus washing them with a baking soda and lime powder solution before storage. The results were eye-opening; after two months, the unwashed eggs had deteriorated, highlighting the importance of proper egg handling and storage practices.

Administrator

11 July, 2024

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Eggs are a type of food with a porous shell that can harbor dirt and bacteria, including salmonella, which can cause diarrhea.

There are currently two different approaches to egg storage in the US and Europe. Some states in the US require farms to wash eggs before selling them, and these washed eggs must be stored in the refrigerator. In large supermarkets in some US states, eggs are displayed for sale in the refrigerated section, and the expiration date can be up to 100 days from the date of laying.

In European countries such as the UK, France, and Germany, the approach is different. Eggs are not washed and are stored at room temperature. The shelf life is between 40 and 60 days.

Wash eggs with baking soda and then soak them in lime water for 30 minutes before refrigerating. Photo: Tan Vu

In Vietnam, there are no standard guidelines for egg storage. Dr. Vu Thi Tan, from Hanoi University of Science and Technology, stated that due to the country’s hot and humid climate, especially during the summer, eggs left unrefrigerated may not remain safe. Additionally, not washing and then storing eggs in the refrigerator can potentially spread bacteria to other foods.

The expert conducted an experiment with two newly purchased cartons of eggs. One carton was left unwashed, sealed, and placed in the refrigerator. The other carton was washed with a baking soda solution and then soaked in lime water for half an hour, allowed to dry, and then also placed in the refrigerator.

After two months, the unwashed eggs showed signs of mold on the shells, and the yolks had become diluted. In contrast, the eggs washed with baking soda and soaked in lime water remained fresh as if they had just been laid.

“Baking soda cleans the egg shells. Soaking eggs in lime water creates a layer of Ca(OH)2 on the surface. When the eggs ‘breathe,’ they release CO2, which then reacts with the Ca(OH)2 to form CaCO3 (lime). This layer of CaCO3 protects the egg shells, preventing bacterial infiltration and keeping the eggs fresh for longer,” Dr. Tan explained.

This method has been around since the early 1800s and has been scientifically proven. It is known as “water glassing eggs.”

The “Boston Cooking School Cook Book” by Fannie Farmer, published in 1886, included instructions on soaking eggs in lime water as a long-term preservation method.

Eggs soaked in lime water for 8 months (left) compared to fresh eggs (right). Photo: Backyardchickens

To implement this method, freshly laid, clean eggs are immersed in lime water, and only removed when needed for consumption. Eggs soaked in lime water retain their freshness as if they were just laid, and their shelf life can be extended to a year or even up to 18 months. Some people have reported consuming these eggs up to two years later.

While this method may not be practical today due to the common practice of purchasing eggs that have already been washed and bleached, it can be applied when you have a large number of eggs. Alternatively, simply washing the eggs with baking soda and lime water before storing them in the refrigerator can help maintain their freshness until you use the last egg.

Frequently asked questions

Eggs can be preserved for months by using a variety of methods such as refrigeration, freezing, pickling, or curing. The key is to prevent bacterial growth and maintain the quality of the eggs. Storing them in their original carton and keeping them in the main body of the fridge, not in the door, helps maintain a constant temperature. Additionally, you can freeze eggs by whisking and pouring them into ice cube trays, or by cracking them into a sealable container with a pinch of salt or sugar per egg.

The best way to store eggs is in their original carton, in the main body of your refrigerator, not in the door. This helps maintain a constant temperature and prevents condensation, which can encourage bacterial growth. Keeping them in their carton also prevents them from absorbing odors from other foods.

Yes, you can freeze eggs. The best method is to whisk the eggs until blended, then pour them into ice cube trays and freeze. Once frozen, pop the egg cubes out and store them in a sealable bag. Alternatively, you can crack eggs into a sealable container, adding a pinch of salt or sugar per egg, and freeze. Salt or sugar helps to prevent the eggs from becoming too rubbery when thawed.

Yes, you can also preserve eggs through pickling or curing. Pickling involves soaking eggs in a brine solution, usually made with vinegar, salt, and spices. Curing involves coating eggs with a mixture of salt, sugar, and spices, then allowing them to dry and cure for several weeks. Both methods create a safe, edible product with a unique flavor and texture.

The longevity of preserved eggs depends on the method of preservation and storage conditions. Refrigerated eggs typically last for 3-5 weeks beyond their sell-by date. Frozen eggs can last for up to a year, while pickled or cured eggs can have a shelf life of several months if properly sealed and stored.