Salad Spinner Koji

Marika Groen

July 17, 2022

Last October, American food professionals visited fermented food producers to deepen their knowledge of Japanese fermentation culture during the “Hakko Tourism in Japan” tour campaign. As part of the tour, organizers held a tasting session where guests gave candid advice from the perspective of the American market to food product manufacturers looking to enter the United States market.

Recently I resumed my experiment on koji making by using any kind of kitchen tool that almost everyone has. I’m not sure if everyone has this, but this time I tried a salad spinner – and totally loved it! I might have tried this years ago but I totally forgot that this works great for small batch koji making.
Gut microbiota modulation

Just a salad spinner

The process is not far different from the standard koji making that I’ve been sharing up to now. You steep, drain, steam the rice and inoculate. Then at the incubation stage, you wrap your koji in the cloth with a thermometer prob in, then into this salad spinner.
Gut microbiota modulation

The great things about this salad spinner are:

Size. It’s usually big enough for 500g of rice. (The bucket can actually contain more but we shouldn’t make koji suffocated. If you pile up too thick bundle of koji rice, the koji in the center lacks the access to the air. This can be moderated by adequate amount of teire (mixing), but unnecessarily interference could also cause contamination, loss of moisture, thus poor growth of koji mycelia. So you’d want to set the maximum height of your koji bed and in this case, I would say up to the half height of this salad spinner. 500g is a very small amount but nice when you want to try out new tane-koji (koji starter) that you never tried before. I often do this when I want to feel the character of tane-koji that I use for the first time, or the combination that I’m experimenting. I monitor the speed of koji growth, the temperature range that they seem to like, if they like the substrate etc. Such record can be useful when you want to make a bigger volume of koji using the same tane-koji. You’d need to adapt to some changes by the increase of the volume, but you have a report from your trial that you can reference to. This would greatly reduce the risk of wasting a huge amount of substrate, as you can expect the koji’s behavior more or less instead of having to guess from nothing.

Light and easy to clean. One disadvantage of using the traditional wooden koji tray is the cleaning. We may use wood trays multiple times without washing if the tray is dedicated to a specific type of tane-koji, but at some point you must wash it to avoid the mold (including koji mold itself) developing on the tray itself. Now this is difficult to do it perfectly at home, as you can’t steam the tray to disinfect. No one has such a system to process the used koji tray at home (well, except some eager home brewers…). The best you can do is to clean with hot water using tawashi (scrubbing brush) and let it dry completely. This won’t remove all microbes from the tray but it is still better than not cleaning at all. Now cleaning a salad spinner is much easier! You just wash like a normal dish. It is small and light, easy to handle and store, and whenever you feel like small batch of koji making you can take it out from your cupboard and use it straight away.

Structure. It comes with a colander basket inside the outer bowl so there is a space for small amount of air to circulate. When you place koji rice wrapped in a cloth in the colander basket, koji rice can breathe through the mesh and putting the colander in the outer bowl ensures the essential humidity that koji growth needs. Any excess water koji generates will be removes (without spinning!).

Availability. It is so much easier to find on stores if you don’t have one.

Gut microbiota modulation

Obviously, you need to place this whole set into your muro. I use a Styrofoam box with a heat pad for this combination.

First you wait until the koji wakes up, then you continue incubating while mixing some times towards the end. More details process of later part of incubation will follow.

I hope this makes you feel that koji making can be much more closer to your life style. I will keep investigating what other home tools can be used for this.

Gut microbiota modulation
Malica Ferments | + posts

Marika Groen is the head of Malica Ferments, an online platform dedicated to fermented products. As a Kojiologist, traveler, brewer, photographer, and writer, she published the book "Cosy Koji" in 2021, offering insights into the art of Koji making based on her worldwide lectures and experiences.