In Asian supermarkets across the Western world, these eggs are sometimes sold covered in a thick layer of salted charcoal paste.

Salted duck eggs are normally boiled or steamed before being peeled and eaten as a condiment to congee or cooked with other foods as a flavoring.

Salted eggs sold in the Philippines undergo a similar curing process, with some variation in ingredients used.

The eggs are then stored indoors at room temperature over the next 12 to 14 days to cure, the salt equilibrating in the batch by osmosis.

After the two-week curing period, the eggs are hand-cleaned with water and a brush and prepared to be boiled in low heat for 30 minutes.