Pickles are an essential part of any traditional Japanese meal spread. Called “tsukemono”, pickles made from many different types of vegetables are eaten with most, if not all meals in Japan. Served in a small dish, pickles are as much a cornerstone of Japanese home cooking as rice and miso soup. The ubiquity of Japanese pickles is only complemented by its diversity. From simple salt-based quick-pickling to the long and involved process of creating ume-boshi, there are as many different ways to make pickles as there are types of pickles in Japan. Today, we’ll take a look at one fairly traditional and enduring method: nukazuke. Nukazuke pickles can be made from a variety of vegetables, including cucumbers, radishes, carrots, eggplants and tomatoes to name a few, and usually possess a salty, slightly tangy flavor while maintaining a degree of fidelity to the vegetables’ original texture. In other words, veggies that are crunchy stay that way.
Nukazuke pickles are made by allowing vegetables to ferment in a bed of specially prepared rice bran, called a nukadoko. Keeping a nukadoko is somewhat similar in concept to cultivating a sourdough starter. Ingredients are combined by weight in specific portions, maintained at a specific temperature and then fed and watered on a schedule to encourage the growth of lactobacillus cultures, which then act as an agent for fermentation for any vegetables buried within it. To start your own nukadoko you’ll need a few ingredients, a suitable container, and about 2 weeks of time.
The container your nukadoko grows in is fairly important in the sense that the fermenting action of a mature nukadoko may be able to degrade unsuitable materials over time. For a nukadoko container, you will want to choose something that has plenty of room, as the nukadoko will need to be stirred for aeration once to twice per day, and any vegetables buried in it will take up space and is preferably made of a material that won’t leach chemicals if it is exposed to acid over time. Plastic is not a great choice, due to this aspect of degradation. Ceramic, glass, enameled metal, and wood are all much better choices for housing a nukadoko. You’ll want something with a wide opening and enough length to bury longer vegetables like cucumbers and carrots easily.
Once you’ve picked a suitable container, it’s time to create the pickling bed. For the nukadoko bed you’ll need rice bran, to cultivate the lactobacillus, salt, boiled and then cooled water, kombu, for flavor, and chili flakes, to curtail the growth of unwanted bacteria. Once the ingredients are combined in the appropriate proportions, the nukadoko will take about 2 weeks to mature. In that time, it will need to be watered, stirred, and fed fresh vegetable scraps periodically. Temperature is also important to cultivating a nukadoko. If kept too hot, it will ferment too quickly and spoil. A lower temperature, such as keeping in the refrigerator, will prevent spoilage, but at the cost of making the nukadoko take longer to mature.
To get started making your very own nukadoko, follow the following steps:
Nukadoko Pickling Bed
800 ml Water
800 g Roasted Rice Bran
80 g salt
2 inch Kombu, reconstituted in water. (5cm)
1 dried tougarashi pepper
6-8 outer leaves cabbage for maturing the rice bran bed. Other vegetable scraps, like carrot tops and peels and celery leaves can also be used. The important part is that the vegetable scraps that are added are leafy or relatively thin, and not too strong in terms of flavor. Onion skin and orange peels are not suitable for this reason.
Boil the water in order to remove chlorine and set aside to cool down.
Place the roasted rice bran into the container that you plan to use to contain the nukadoko.
Add salt to the roasted rice bran and mix together thoroughly.
Pour the cooled water into the container with the rice bran and salt, and mix well using your hands.
Bury the kombu and chili pepper completely in the rice bran.
Flatten the surface of the rice bran with your hand, and wipe any excess off of the sides of the container with a damp cloth. This helps to discourage unwanted bacteria growth, and then place the lid on the container.
Refrigerate the entire container overnight to rest.
The next morning, remove the container from the fridge and press the cabbage leaves/vegetable scraps into the rice bran pickling bed (nukadoko) and bury them completely with rice bran.
Wipe the inside of the container with a damp cloth to clear any rice bran that may be sticking to the sides.
Place the lid on, and leave it overnight at room temperature.
The next day, remove the cabbage leaves from the rice bran bed, and stir the bed well, making sure to turn it over completely. This allows air to reach the bacteria living in the bed, and is essential to prevent over or under fermentation.
Add another cabbage leaf, burying it completely. Then flatten the top surface of the bran and wipe the inside walls of the container clean with a damp cloth.
Repeat the above process, adding vegetable scraps and turning the nukadoko over three to four times. This should take about one week, if kept at room temperature, and 3-4 if kept in the refrigerator. Once your nukadoko is ready to pickle, it should have a fresh, slightly sour smell to it.
To pickle vegetables using your nukadoko, carefully wash them, and cut them to the desired size before burying in the rice bran bed, using the same method as was used to bury the vegetable scraps. The pickling time of each vegetable will vary, as it is dependent on both the composition and size of the vegetable.