Montag, 31. Oktober 2011

Nukadoko - starting a rice bran pickling bed

After reading a lot (e.g. visit Hiroyukis blog ) about this japanese pickling method, I decided to just give it a try. Nukadoko (ぬか床 = bran bed) is based on bacteria driven pickling as sauerkraut or traditional pickled cucumbers. But instead of using plain vegetables and salt it also involves a fermentation process based on grain - think  rye sourdough. The grain in use is rice bran. After the bran bed starts the correct fermentation process different vegetables can be pickled without much ado.

It may be easy to buy preprocessed rice bran at rice stores in japan - for small money. But here the situation is totally different: No rice stores. It took me quite some time (several weeks) to get hold on rice bran appropriate for human consumption and not been sold at pharmacies in little units for high prices. You could buy rice bran in huge units for small money just ordering it at farm stores: declared as horse food. But all horse products have additives as vitamines, calcium and so on. Maybe good for glossy horse fur and firm bones for high jumps, but I was in need of something for a pickling bed without fancy food chemistry involved. At least I found a mill selling rice bran of organic grown rice in 1 kg bags. Made of rice only and nothing else.
I ordered 3 bags for one pickling bed. 2 kg to start, 1 kg for feeding the bed from time to time.
I followed several suggestions concerning the kick off so I took:

2 kg rice bran
400 g salt (I used plain salt without any additives)
2 l water
1 slice french white bread soaked and mashed in water
2 cabbage leaves

Additives for flavour development
1 piece kombu
2 big slices of finger ginger
2 starfish chillies halved (ginger and chillie may diminsh bad bacterias)

I decided on bread because I made  some experiences with fermentation processes without any seeding/starters: It took much time, the development of good bacterias didn't kick in therefore it often turned bad. So I am going to give it a quick start. First I was thinking about adding one tablespoon dried sour dough starter but I decided against it. This was my idea knowing a little about physiology and food chemistry but I didn't find any recommendations.
Before mixing the bed I had to toast the rice bran. Sources recommend to heat the rice bran up to 70 C to kill bad bacteria but not much higher. I used a very big and deep pan and roasted 500 g batches over medium heat while turning the bran carefully all the time with the help of a wooden spatule. Beware: this is a very annoying business.  (Since the son left our home I am missing a slave for this kind of tasks. He was always very useful for a little bit of pocket money).
At least the bran browned nicely in a deeper shade of light brown. I messured the temperature of the bran once in a while. The roasted bran went into a big wooden bowl to cool down. Afterwards I transferred the bran into the storage container: a food proof plastic bucket (10 l) with a lid. I think this size is very convinient for the propper turning and mixing of the pickling bed (you have to do this twice a day) and to take under vegetables of different sizes.
Meanwhile I boiled 2 l water and let it cool down until lukewarm. I desolved the salt in the water and added it to the bran. After incorporating the water, the bed reminds me of soft clay for pottery. Sorces recommend: Moisture and texture should remind of miso - I guess this is it. Than I added the mashed bread, ginger and chillie and mixed it in. I placed the cabbage leaves and kombu in different layers into the pickling bed and finished with a layer of moist bran, which I pushed and patted until firm and flat to make sure there was no air left in the bed.
View of the bucket
I put on the lid rather loosely and placed the bucket in an open storage unit in one kitchen corner near the radiator. The room temperature is always around 20 C and this should be good enough. During hot summer times I would have placed the bucket in my basement.
I hope this will work out - somehow. The next days will show the results. I may start pickling vegetables soon or give it a new try changing the ingredients.


Hiroyuki hat gesagt…

You did it at last! It's kind of exciting (laugh)! I hope your nukadoko will be fully fermented soon and, above all, you will like the flavor of nukazuke.

One thing I wonder is whether bread will have a positive effect on your nukakodo, because as far as I know, vegetable lactic acid bacteria will come from the cabbage leaves and I wonder if bread has living yeast (and vegetable lactic acid bacteria) in it.

Fräulein Trude hat gesagt…

Yes, it is kind of thrilling.

Bread should add both (but on uncontrollable level): vegetable based lacto bacilli and yeasts - still there is a minor risk of breeding mold too. This is the reason why I was thinking to use dried sourdough starter.

Hiroyuki hat gesagt…


Yes, that's what I feared, too, so I refrained from adding any bread (or beer). No dried bonito, either, or anything of animal origin because otherwise the nukadoko could get wormy.

Sissi hat gesagt…

Congratulations, Kiki! I made nukadoko last year and must say it was a very exciting experience.
I still have some rice bran and just need to wait for lower temperature outside so that I can find a badly heated spot in the house (it's 25 or more degrees all day now).
Good luck!

Fräulein Trude hat gesagt…

Sissi: Did you freeze some of your old pickling bed to start a new one? I read nukadoko will get better and better with time going by like sourdough. Lucky my house has different temperature zones. 25 C is nice. I wish I had 25 C right now. I would place the nukadoko in the basement / laundry room. Some oracles say we will have to face -25C in only a few weeks. But right now we have a really wonderful, mild and most colourful autumn. It is such a waste to spent time at the office.