There is one type of century egg which is prized over all others, yet they are just a matter of luck, really. With 松花蛋 (sōng huā dàn), literally 'pine flower eggs', the processing of the egg leads to the formation of these 'pine flower' patterns in what was the white of the egg. They make no difference to the taste, at all, but can be very visually attractive. I shelled two eggs this morning for my congee; the first was uniformly black but the second had formed 'pine flowers'. Lucky me!
松花蛋
Both went into the congee which had been slow-cooking all night. Also added some fried lean pork and enjoyed 皮蛋瘦肉粥 (pí dàn shòu ròu zhōu) for breakfast. Looks dull after the pine flowers, but tasted just fine, thank you!