Mineral oil works as a protective coating that prevents eggs from picking up odors as well as slowing the deterioration and drying of the egg during long-term storage. For the best results, eggs should be dipped in mineral oil within 24 hours of being laid, making this method ineffective for store-bought eggs. Use only clean, unfertilized eggs for long-term storage. Eggs should not be washed before storing, as this removes the egg's natural bloom, a protective coating which helps prevent bacteria from entering the egg. For eggs that require cleaning, do not use this method of preservation.

To preserve eggs for storage using this method, you do not need to heat the mineral oil before use. Submerge fresh, dry eggs at room temperature into the mineral oil using a wire basket to preserve many at a time, or individually using a spoon or ladle. Remove the eggs and allow them to drain briefly on a rack to remove the excess oil. Place the eggs in a carton or case with the small side down to protect the larger side's air cell.

While room temperature storage is possible using this method, you will recognize better long-term storage using cooler temperatures. Store cartons or cases of eggs in a cool location such as a basement, ensuring that you do not subject them to freezing temperatures in a completely unheated storage area. Keep eggs in storage until ready to use, but do not exceed eight months, as undesirable odors and flavors will develop in the egg beyond this time.

When using preserved eggs, be sure to cook them thoroughly and practice good food safety and handling hygiene. While incidence of spoilage is low when using this method, as with any food item, it is possible. Spoiled eggs produce a strong sulfur smell that will be immediately discernible upon cracking the shell; discard any spoiled eggs without cooking. Once oiled, eggs are not suitable for making cakes and whipping, as the oil interferes with the foaming ability of the egg's white.