Nuka-zuke pickles (糠漬け)
Nuka-zuke (or nukamiso-zuke), which is also called dobu-zuke or dobo-zuke, is one type of representative pickles in Japan, made by pickling vegetables in nuka-doko (a rice bran bed made by lactic acid fermentation). Sometimes it refers to the way of pickling. In general, juicy vegetables such as cucumber, eggplant and Japanese white radish are often pickled, but others such as meet, fish, boiled eggs, and konnyaku (a gelatinous food made from devil's-tongue starch) are also pickled. The one which is pickled during a short time is called asa-zuke (young pickles) or ichiya-zuke (overnight pickles), while the one which is pickled over a longer period is called furu-zuke (old pickles) or hine-zuke (matured pickles). In addition, a dried Japanese white radish pickled in a rice bran is called Takuan-zuke (yellow pickled radish).
In the past, each household had nuka-doko and made nuka-zuke, but recently most of the people buy it at the supermarket to avoid the pain and a smell of rice bran bed. However, nuka-zuke is a popular food even today, so many people consider the breakfast of boiled rice, miso soup and nuka-zuke as an image originating in the Japanese mind. It is often eaten as something to nibble on while drinking.
It is said that nuka-zuke of the present form was created at the beginning of the Edo Period. It is said that originally pickles were made using grain and soybean ground by a millstone as a bed, which was called suzuhori in Nara Period. Nuka-zuke was established using rice bran instead of grain and soybeans which were produced at the time of rice milling during the Edo Period. It is thought that vitamin B1 of the rice bran being absorbed by vegetables prevented beriberi to some extent that was prevalent in those days.
The manufacturing method
At first, make nuka-doko. Add a 15% salt solution, cooled after boiled once, to rice bran (sometimes used after roasted) of an appropriate amount. Add enough water so that nuka-doko becomes a little harder than miso. Putting it with cayenne pepper (red pepper) and konbu (a kind of kelp used for Japanese soup stock) into a pot or a plastic container and making the surface smooth and flat, nuka-doko is ready. Pickle scraps of vegetables, changing them every day for approximately 1 week. However, the pickle is less tasty because nuka-doko is not matured at this stage. Fermentation advances by pickling the vegetables and daily attention will enhance the flavors. Delicious nuka-doko is ready to eat within approximately 4 months in wintertime and within 2 months in the summertime.
Because matured nuka-doko is sold in a container in a large grocery store makes it convenient. In addition, given a small quantity of nuka-doko (called toko-wake - bed sparing), it is possible to make matured nuka-doko in a realtive short time. Some people pickles the skin or rind of fruits to add flavor.
Pickling vegetables washed well and rubbed with salt in the finished nuka-doko, nuka-zuke is ready. The time of pickling depends upon the size of the vegetables and the season; for example, a whole cucumber can be ready in half a day. If it is not pickled very much, add some soy sauce and eat it, and if it is too pickled, cut it into small pieces and juice it a little to add as ingredients for boiled rice with tea poured over it or add it to fried rice. Generally it is eaten after washing, but sometimes eaten with rice brain without washing.
In order to prevent nuka-doko from rotting, it is necessary to stir it every day from the bottom and mix the part which touched the air into the depths. In the summer when the temperature is high, sometimes it needs to be stirred twice a day. If you finish stirring it, level the surface of nuka-doko, wipe rice bran on the edge and cover it lightly. In addition, because is easy for nuka-koko to break down like water with pickled vegetables, absorb the water with a dish towel or newly add rice bran and salt once a week to bring back the hardness.
When you can not take care for a long time because of a trip, etc, you can prevent it from rotting for a while by adding extra amounts of salt on the surface and then placing it in the refrigerator. When fermentation advances too much and nuka-zuke becomes too sour, add crushed eggshell. When you want to make the color of eggplants' skin bright, insert an iron nail or an iron utensil which is sold exclusively for this purpose. If you put in an iron nail with a sharp point, there is danger that you'll get injured when you stir it, so it is necessary to blunt it for safety. When there is a pungent smell (similar to the smell of glue made of synthetic resin or a smell of thinner), you may pour in some salt water and stir it.
In addition, nuka-doko cared for properly gives out a peculiar smell of fermentation which is not unpleasant, so that you had better put it in a cool, dark, and well-ventilated place.
Attention for health
Because nuka-zuke is a preserved food and includes a lot of salt, obviously you should take care not to eat too much that would that would result in an over consumption of salt. In addition, it is said that rice bran and the skin of vegetables tend to easily retain agricultural chemicals. Since rice bran uses a few agricultural chemicals, it is advisable to newly remake nuka-doko every year to prevent the accumulation of agricultural chemicals in nuka-doko.