Pickled egg

Pickled eggs are typically hard-boiled eggs that are cured in vinegar or brine. As with many foods, this was originally a way to preserve the food so that it could be eaten months later. Pickled eggs have since become a favorite among many as a snack or hors d'œuvre popular in pubs, bars, and taverns, and around the world in places where beer is served. After the eggs are hard-boiled, the shell is removed and they are submerged in a solution of vinegar, salt, spices, and other seasonings. Recipes vary from the traditional brine solution for pickles to other solutions, which can impart a sweet or spicy taste. The final taste is mostly determined by the pickling solution. The eggs are left in this solution from one day to several months. Prolonged exposure to the pickling solution may result in a rubbery texture. A common practice is to puncture the egg with a toothpick to allow the pickling solution to penetrate to the egg's interior, but this is dangerous as it can introduce Clostridium into the finished product. Eggs prepared with this method have sometimes had high enough levels of botulinum toxin to cause illness in a human.

Source: Wikipedia