Archives for posts with tag: Mold

I made this jar of cucumber pickles last week. I didn’t notice that the rubber sealing ring broke, a lot of air flowed in and within a week the the mold grew profusely into a fluffy covering. If it had been a tiny bit of mold I could take it off, put on a new rubber ring and let it continue fermenting, but this is too much, and out to the compost it goes. My compost will love it!

A journalist came to find out some more about ‘mold in food processing’. What could be a better way to start the miso season. I prepared soybeans and then made a batch of rice miso when Hanna Dahlström came. 

The happy result.

We also discussed mold growing (and use) in detail – how to make the rice koji etc, but that process takes about 5 days, so no hands-on demonstration this time. 

I have enough koji left from earlier this year for several miso batches, and I will be making more koji in January and February for miso production next year. 

The mold (Aspergillus oryzae) is growing great with 12 hours left to go.  


I noticed this the other day among my jars of fermenting miso.

It is a thick layer of mold on top of a miso I made only a month ago. A lot of air must have been flowing in. I was thinking of throwing it all away, but I cleaned the mold out first.

It looked and smelt very good, so I found the problem with the seal, changed lid and rubber rings and put it back to ferment. I’ll keep an eye on it, but expect it to turn out as good as the others. In my experience fermentation transforms all ill.

Not at all bad miso!

The first batch of organic polished rice koji has grown very well and is now laid out for drying above a heat radiator emitting the sweet fruity fragrance of grapefruit with a slight tinge of cat piss.

This will be a steady scene as new batches come from the incubator over the next month or two.

The air in the house becomes saturated with spores from the mold. We often see koji mold growing in the dirt around potted plants. It is said that in old Japanese farm houses they didn’t have to add koji spores but just left the steamed rice out to become inoculated with the spores from the air.

In the meantime, I’ve also been making rice koji – a new batch every third day. I’m up to 4 kilos now and will do 2 more batches and then switch to making about 5 kilos of barley koji. I do have a larger incubation chamber, so I could make bigger batches faster, but I prefer the slow, steady pace of the smaller ones.

Yesterday I ran out of my japanese tane koji (koji starter), so I got out a package from a company in Olympia Washington USA.

I bought this last year when I was visiting over there, along with starter for barley koji and tempeh. It is so easy to find and contact these companies by internet now days.

Step 7

The morning of the fourth day

The mold has not blossomed yet but is just starting to. The fuzz of the mycelia is beautiful, and the odor and flavor are wonderful. The enzyme level should be at its very best now, so I will harvest it anyway.

On flowering it will turn a nice yellow tan color. Many koji makers let it go that far. Perhaps this adds to the flavor and color of the miso. I seldom let it go so far and haven’t noticed any difference in the miso.

I scrape the mass onto cloth lined drying baskets and spread it out.


These baskets go on a rack in the furnace room to dry for 2 or 3 days.

The next and last step will occur in about 2 days when I check for dryness, package and save for later miso making.

And now is the time to put rice to soak for the next batch. I will make up to ten batches of rice and barley koji during the winter season.

Step 6

Now is the evening of the third day

The mold has been growing in the heat cabinet for 2 days at about 27 degrees centigrade. The rice now has a furry covering of aspergillus mold which cakes the whole mass together. The dampness, odor and taste are perfect.

Usually I harvest it at this time, but this time I think I will let it grow 12 more hours to get a little color as the mold flowers. So I aerate again and put it back into the cabinet.

Next step tomorrow morning – harvest

Step 5

The morning of the third day

Again we do the same as the last 2 steps. Aeration is very important. Everything is developing quite nicely.

We can now see traces of the mold growing. The humidity is just right. And the odor is developing into the sweet, flowery, fruity bouquet characteristic of the Aspergillus oryzae growing on rice.

We’ll have a look after another 12 hours this evening.

There hasn’t been much activity concerning gardening or cooking going on here lately that is interesting – until I threw together todays dinner.

The sautéed vegetables with noodles, parboiled kale, lactic pickled carrot and fried tempeh looked pretty good and tasted even better, so I took this picture and the opportunity to write about tempeh.

Tempeh is a traditional fermented soyfood from Indonesia. For hundreds of years the people of Indonesia have been inoculating boiled soybeans with the fungus Rhizopus oryzae (naturally occuring in the environment). They then leave the beans to become infused with the mycelium of this mold until it all becomes a solid mass which can be sliced and fried for a meal. The soybeans become partially predigested and thus easy on the stomach. The taste of it changes too, to something more like chicken, they say. I, however, think it has its own distinctive, wonderful flavour.

Today I fried the tempeh slices in lots of olive oil with one dash of herb salt and another of tumeric powder on each side.

In the 80,s I made my own tempeh in an incubator for temperature control, with mold spores from a lab, but now we buy excellent (better than my own) fresh tempeh from Holland.

Besides, my incubator is not functioning now. I have to get in and look over the electric system. The thermostat probably has to be replaced. And soon too, as I must get busy growing mold for home miso production.