Episode notes
Century eggs are duck eggs cured in a strongly alkaline coating until the white becomes translucent brown jelly and the yolk turns into a dark, creamy center. This episode explains the chemistry behind the change: raising the pH to between 9 and 12 breaks down proteins into savory amino acids and produces the dish's famous ammonia smell.
We look at Ming dynasty records, folk tales about duck eggs found in mortar or a forgotten ash pit, and the traditional recipe of tea, quicklime, sea salt and oak ash. We also cover modern shortcuts, a 2013 scandal over industrial copper sulfate, the horse urine myth, popular ways to serve the eggs, and their very high sodium content.
- How hydroxide ions pass through the shell and break down proteins, and how this compares to ceviche
- Where the frost-like pine patterns on the best eggs get their name
- Why lead oxide and industrial copper sulfate shortcuts were dangerous, and why zinc oxide is used instead
- Why the Thai and Lao names gave rise to a false horse urine rumor
- Serving ideas including black vinegar, pickled ginger, silken tofu, and century egg and pork congee