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Home Brew Sake

March 29th, 2018 at 2:51 pm

Koji-kin from Scratch, well sorta

One question I get fairly regularly is how to make koji-kin. Despite this I have failed to take the time to write up a good explanation for all of you. Well, no longer. In this article I will explain just what it takes and how to do it. Almost all you need to know is in my “Video Series and Instructions for making koji for sake” at: link. The only thing missing for making koji-kin from that source is that you need to sustain the last stage longer. That is, don’t spread out and cool the koji once it has completed its coverage of the rice. Rather, continue to monitor the koji so it does not get too warm or cold. It will start to show signs of a greenish yellow tint. This will progress into a darker greenish yellow color and begin to cover each grain. Once fully covered, carefully spread out the koji to cool. The green covering has lots of tiny spores that will come off so you’ll want to minimize disturbing it. After it has cooled, it needs to be dried so that other contaminates will not find it to be a nice home. Once FULLY dry, and I mean dry, you can place it in a shaker for later use.

The following picture is some koji-kin rice I have made. Some people will grind this into a powder but I’d use it as is.

Koji-kin rice

Koji-kin rice.

One way to use it is to put it into a shaker like the one in the following picture. It was purchased at a kitchen supply store and is often used for powdered sugar and the likes. It works well for koji-kin rice.

Koji-kin rice shaker.

Koji-kin rice shaker.

Using this shaker and koji-kin rice to shake over a piece of paper I get the pattern in the following picture.

Koji-kin from shaker.

Koji-kin from Shaker.

If you regularly make koji for your sake, you can, as needed, increase the batch size by 50% and after collecting and cooling the koji when ready, let the rest continue on as described above. This lowers the extra effort required for making your own koji-kin sense you were doing all most all the work needed already. Care must be taken to ensure the koji intended to continue on to koji-kin does not lose its warmth. Its smaller batch size will not hold its own generated heat as well as the larger batch.

Let us know if you make your own koji-kin and what your experience has been like!

  • Rheuben
    5:26 pm on July 1st, 2018 1

    Great resource many thanks

    My prior batches I was fortunate enough to source pre made koji from a local miso producer. as producing Koji seem like an excessive investment for a first time brew. the other thing that got me was importing into NZ can be a hassle as shipping here is painfully slow. so if I was to purchase I though it would be more beneficial to maintain my own culture of koji kin.

    My key questions was what is the shelf life of the koji-kin and how do you best dry the end product to avoid undesirable contamination.


  • Will
    9:20 am on July 2nd, 2018 2

    Hey Rheuben,
    Koji-kin will last a long time though I don’t have any statistics on it. The spores naturally are waiting for a good environment to spring back to life.

    For most of us who don’t have any special equipment or dryers it is best to dry the koji in an area that is as undisturbed as possible. This is to avoid air movement carrying in contaminates. However, I have not seen many issues with this.


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