There are several methods known to preserve eggs for a long time without using a refrigerator. One involved completely immersing the eggs, clean and dry, in a powdery substance such as charcoal, chalk, sand, wheat bran or even very dry sawdust. The other was complementary to the first and required covering the shell with a liquid substance that, when solidified, formed an impermeable surface. Wax, grease, paraffin, tallow and Vaseline were suitable for this procedure. Afterwards, the egg could be immersed in the powder following the first method. Both procedures had the same principle in common, that is, preventing the passage of air and microorganisms through the porous shell.
Considering that eggs were especially abundant in the periods April-May and August-September, August and September were the ideal months to start stocking up for the winter, especially since the eggs were not fertilized and cost less than in other periods of the year.