Pickling is one of the oldest methods of preserving the flavor and nutrients of fresh vegetables. In Japan, pickles (tsukemono) are classified by the main ingredient, the pickling medium and the length of pickling. Most pickles are vegetables but sometimes meats and fish are used. The pickling medium can be vinegar, salt, sake lees, miso or rice bran. Some vegetables, like the cucumber, may be quickly pickled in just 30 minutes (asazuke) while some items are left to mellow for much longer (furuzuke).
The most common vegetable pickled in Japan is the daikon. It is generally pickled in rice bran — nuka, the byproduct of polishing rice — for a few days to several months (to produce a true takuan). Most households in the countryside still maintain their own nuka pickle pots, called nukatoko. Special buckets, lids and weights are sold just for this method of pickling.
The simplest Japanese meal — ichiju issai — consists of a bowl of hot white rice, one soup and one vegetable, generally a pickled daikon. Adding more courses and side dishes creates variations on this simple theme, but the core elements, especially the daikon pickle, remain the anchor of the meal. For the adventurous, maintaining a pickle pot can raise a cooking hobby into a flat-out gastronomic obsession.