The best preservation methods for earth eggs are: keeping them in a cool and ventilated place, avoiding washing and rough operation, storing them in white sand or rice, storing them in refrigerator, and cooking them before storage.

1. There is a cool and ventilated place: storing soil eggs in a cool, ventilated and dark place can keep the eggshells from cracking or discoloring, and keep them in a natural and fresh state.

2. Avoid washing and rough operation: Do not wash and wipe the eggshell easily, so as not to damage the protective film on the eggshell surface, which may easily lead to the infiltration and pollution of the eggshell and the liquid in the egg.

3. Store in white sand or rice: Putting earth eggs in white sand or rice can effectively increase the porosity of eggshell surface and reduce the chances of bacteria entering, and at the same time, through the sterilization of white sand or rice, the reproduction of bacteria can be effectively controlled.

4. Store in the refrigerator: Put the eggs in the refrigerator, and don't store them with other foods with strong taste. This can reduce the temperature, and then slow down the metabolism of egg yolk and protein, thus extending its shelf life. The correct storage method is to put the big head up and the small head down, not horizontally, so that the yolk can float and stick under the air chamber, which can not only prevent microorganisms from invading the yolk, but also help to ensure the quality of eggs, avoid yellowing and prolong the storage time.

5. Cook and then store: For free-range native eggs, it is the best measure to ensure food safety because native eggs are more likely to carry bacteria.