Koji in an Instant?

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The Struggle

The instant pot has been a hot kitchen item for the last year. It’s understandable due to its versatility, convenience, and safety. With its wide range of cooking temperatures and options, it’s no wonder people are testing its limits. We recently had a customer attempt to make koji in an instapot and they weren’t sure if it was working properly. So they asked

“Can you use an instant pot to make instant koji?”


Our customer used the yogurt setting on low. The manual states that you can make jiu niang, a fermented rice dish. This is true: that dish works great in an instant pot, as does other fermented dishes like natto. So this should be perfect for koji. Or so I thought. But the big difference between those dishes and koji is that they are bacteria-based fermentations and koji is mold-based. Unfortunately, the spores on koji need a pretty specific environment to grow and an instant pot is not one of them. The instant pot retains too much moisture and tends to drip back on the koji, even if it’s covered with a towel. This is not ideal. The koji needs to be held at roughly 90°F. The koji will start to generate its own heat and you will need to rotate it to keep it below 108°F. The instant pot on the low yogurt setting measured 110°F when I tested it. The koji will not survive long at that high of a temperature. I tested the entire method for koji in the instant pot – it did not work for me as the mold spores did not grow, nor did the rice have the correct smell. So it’s sad to say, but this isn’t our way into an easier method for koji.

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  • Beth A. Baron
    August 4, 2019 1:46 am

    I have a new instant pot. I would like to try making yogurt out of a congee by making watery rice, adding my favorite sheep milk yogurt, and using the yogurt setting. I’m sure there are pitfalls in this plan because I have seen nothing like it in my internet searches. Do you have a recommendation of how to try this? Thanks!

    • This sounds like it could work but it also sounds like it could be a recipe for food borne illness. If you do attempt this make sure everything is sanitized and sterilized before adding it to the pot ( well everything except the yogurt).

  • jonathan d wint
    December 16, 2019 6:09 pm

    I looked at this and I think a easy way fix it would be to put in a spacer.. And use a Jar.. I will report back my findings

  • I grew koji successfully in an Instant Pot using the yogurt setting on ‘less’ which has an operating temp of 30-34 degrees C (perfect for koji, right?) I used bamboo rice steamers inside the Instant Pot with the inoculated rice in 2 layers with good air circulation, and a bamboo steamer lid on top (not sealed). It worked great!

  • Thank you H for your great description of your Instant Pot method.

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