Japanese food has such a unique variety of food such as; natto, miso, umeboshi (plum pickles) and nukazuke ぬか漬け. Today I will introduce Japanese Nukazuke here. Some of you probably have already known this super food. However, it’s a bit of tricky to keep it right conditions all the time. I had actually tried twice in Australia from scratch but no success both times. However, I have found a way so I finally manage to keep it right.
What is Nukazuke?
So, what actually Nukazuke ぬか漬け is Japanese traditional pickles made by Nukadoko, rice bran beds which is fermenting lactic acid bacteria. We commonly use some vegetables such as cucumbers, eggplants, and radish. It is said that it was the early Edo period ( between 1603 and 1868) that the current style of Nukazuke has been established. Basically, Nukadoko is only made with rice bran, water and salt. It will take for 2 or 3 weeks to ready to pickle.
Nukazuke’s salt makes vegetables’ moisture comes out and it helps lactic acid bacteria and yeast bacteria grow inside of Nukadoko. And these bacteria and yeast are the mechanism to make delicious pickles. And vitamin B1 increases in the process as well as protein, dietary fiber, vitamin A, B group, E, calcium, phosphorus, zinc, iron can penetrate vegetables.
How to make Nukadoko
There are different types of ingredients which depends on the family recipe but basic method is same.
Firstly, you need :
- Nuka, rice bran (米ぬか)……2kg
- Salt (塩)……200g（10%of rice bran）
- Water (水)……2kg（2L）
- Sea weed (昆布)……2 of 15X10cm sea weed
- dry red chilli (赤唐辛子)……5
Then mixed all together.
However, still a bit of confusion, this is not it. You have to wait and grow lactic acid bacteria and yeast which will take at least 7 days, depends on the room temperature. I have failed that process because I made them in summer in Australia, it gets up to over 35 degrees sometimes and average is 27 to 30 degrees. So, it was too hot and I didn’t look after them very carefully.
Must do list till Nukadoko ready
- Put the wasted vegetables and stir it twice a day. Wasted vegetables such as a head of carrots, zucchini, daikon and cabbage can be used to help grow yeast and bacteria in Nukadoko. You have to mix well twice a day (morning and night) till it get ready to pickle.
- Changing wasted vegetables every 2~3days. This will also help to grow yeast and bacteria freshly rather than old vegetables and these vegetables’ water will help as well.
- Keep doing this process for a week.
This process calls Suteduke 捨て漬け, during this process these pickles are just only salty so you can’t really eat them, well you can but there are no flavours, though.
How to put and keep Nukadoko healty
After a week or so, when the Nukadoko is a bit sour, yeast and lactic acid bacteria are ready to make your vegetables yummy. So it is time to get pickle them! However, there are a few points to make sure:
- Don’t put too many vegetables and make sure there are enough room between them.
- To completely sink vegetables into Nukadoko.
- Firmly extract air from Nukadoko.
- Flatten the surface of Nukadoko before you get the lid on.
Normally, Nukazuke will be ready by 24 hours but it depends on the room temperature if too hot, it will get early to ready and if it is cool or cold weather, it will get slow.
Basic Knowledge of Nukadoko
Suitable temperature of Nukadoko
Important lactic acid bacteria live on Nukadoko, it is said that the optimum temperature for its activity is around 20 ~ 25 ℃, and this lactic acid bacteria ferment the vegetables and make delicious pickles. However, if the temperature is too high, this lactobacillus fermented excessively and it became too sour. I think that the reason why I failed these Nukadoko three times to manage this temperature.
Must Stir Once a Day
Microorganisms such as lactic acid bacteria, yeast, butyric acid bacteria and so on are living in Nukadoko. This balance is very important, and it is to keep the balance of these microorganisms optimum to stir Nukadoko every day. Lactic acid bacteria actively increase in an environment without air, and butyric acid bacteria actively proliferate in an air-free environment like lactic acid bacteria. On the other hand, yeast has the property of preferring oxygen.
Therefore, if you do not stir every day, abnormal fermentation happens;
- When lactic acid bacteria increase too much, it gets sour
- If butyric acid bacteria increase too much, there is a bad smell
- When yeast is increased too much, a white membrane sticks to the surface
However, you can fix Nukadoko when these things happened, don’t worry your Nukadoko baby will be fine.
I will tell you when you Nukadoko gets sour.
Too much water?
As you continue to soak vegetables, a lot of moisture will come out of the vegetables, then Nukadoko will be soften. Such softened Nukadoko tends to be excessively fermented, causing it to become sour. Open the lid of Nukadoko container, if you have a puddle, suck it up with kitchen paper. Also, let’s adjust it by adding bran s as necessary.
Not enough salt?
In Nukadoko, salt of Nukadoko is absorbed into vegetables and as well as salt content contained in Nukadoko will decrease from moisture of vegetables. As this amount of salt decreases, lactic acid bacteria become active and the amount of acid generated increases, which causes sourness.
Method 1: Adding some salt
Remove vegetables from Nukadoko and add salt of about 15% weight of the bran bed and stir. The best thing is to remember the taste of the branded floor in a good condition. Let’s check the taste for a while when “Delicious Nukaduke” is pickled. By doing so, you can understand the salt concentration. However, if possible, it would be better to add salt while watching the pickled vegetables. Let’s not get a lot of salt from the beginning, as you get impatient as it gets sour. Also, when adding salt, just stir Nukadoko, just let it rest for a few days without pickling the vegetables.
Method 2: Adding Nuka (rice bran)
As long as the bran is still pickled, I will lose weight, so I will add some bran sometimes. With this you can suppress the sour a little.
Method 3: If it’s hot weahter
it’s simple. Let’s put it in the refrigerator. Lactic acid bacteria abnormally ferment and become sour when temperature rises. So being in a refrigerator is to lower the temperature. If the fridge can not fill in, you can use a frozen plastic bottle or coolant.
Method 4: Adding Egg shells
This is a very traditional way, put the shell of the egg. However, because egg shell has Salmonella bacteria, boil it in boiling water, peel off the inner thin skin, dry it, and put it in Nukadoko to relieve it. Calcium contained in egg shell neutralised acidity.
Method 5: Adding some baking soda
Baking soda also acts to neutralize acidity. I put baking soda more than the egg shell. Since sodium bicarbonate is weakly alkaline, I put in 2 teaspoons of teaspoon (2 kg of rice bran).
Method 6: Just rest the Nukadoko
Anyway, I will rest the Nukadoko. If you do the above countermeasures, I will give it a rest for about two or three days. By doing this, lactic acid bacteria causing sourness will calm down, and nature and sourness will be gone. And please be sure to clean up the circumference of the container.
Where to get Nukadoko?
Well, it’s really hard to get Nukado from overseas but there are few Japanese grocery store in all over the world nowadays so ask around these shops. However, I suggest if you have enough money to get “ready made Nukadoko”. I wan’t sure that this time around I could get success Nukadoko so that I ordered “ready made Nukadoko” from Japan. It’s of course organic Nukadoko and it ready to pickle some vegetables when it get arrived. There is no waiting period or anything like that.
I have attached some of link which you may like to use translate tools from Google and using optimum forwarding service.
Optimum forwarding service:
Ready Made Nukadoko:
Nukudoko Starter kit: