I love salted eggs. They are dirt cheap in the Far East but quite expensive over here in England cost around £2 - 3 for a box of six.
Those salted eggs imported from China (not seen in England) usually has a thick black ash coating to preserve and protect the egg. Over here in England salted eggs look just like a box of normal duck eggs in an egg box.
It is dead easy to make your own. Simple ingredients just sea salt (best use unrefined and no preservative), eggs (duck or chicken), a little rice wine or cooking wine and water.
For the preserving liquid, every 1 litre of water adds 200g of salt. Boil this and stir till all the salt has dissolved. Leave to cool completely. Add 2 - 3 tbsp of Chinese rice/shaoshing wine.
If the eggs are mucky, clean and wipe dry with a clean cloth or paper towel. Make sure the eggs are not dented or showing crack line.
Take a squeaky clean container or glass jar (I normally use a lock n lock box). Fill the box with eggs to the top, quite tightly together but not squashing the eggs till they break. Fill the box/jar with the salted liquid right up to the top. If the eggs float on top of the liquid, use something like a saucer plate or mesh to anchor the eggs down so they are all fully immersed into the liquid.
Cover and leave in a cool dark place for 4 weeks, then ready to eat. These preserved eggs will keep for few months immersed in the salted liquid.
The preserved yolk when matured will solidify into a golden - orangey ball while the white will look exactly like a normal raw egg white but salty. Colour of the yolk depends on the original yolk pigment. Normally salted eggs are made with duck eggs, chicken eggs are also suitable and cheaper but the yolk will be much smaller.
Salted eggs can be boiled and eaten with rice or rice congee.
Or use it raw and mix with omelette, steamed meat cake etc.....
Or use the egg yolks for making mooncakes or zhongzi