Amazing Koji Mold World: 18
Marinating Tofu in Shio-Koji

Written and illustrated by Misa Ono

At first, I enjoyed marinating vegetables, meat, and fish in shio-koji (salt-koji). However, I realized one day that I came to be unsatisfied with those things only. I was really eager to marinate other things and tofu came to my mind! There is a traditional method of tofu marinated in miso in Japan. When marinating drained tofu in sweetened miso, the taste of tofu becomes like cheese and it is wonderful. Inspired by it, I thought koji can be used instead of miso. Because tofu contains lots of protein, enzyme of koji may break down the protein into amino acid and it may make good flavor. Thus, I spread koji around drained tofu and wrap with cling film. Then, I put it in a plastic bag and left it in a fridge. The report of marinating tofu in shio-koji is the following.


Day 1-2: Taste like salted normal tofu.

Day 4-5: Taste like salted normal tofu but there is a hint of cream cheese.

Day 7-8: Wow! It has cream cheese flavor overall!!

Week 2-3: Gained acidity. Some favor it but others don’t. It can’t be expected to change the flavor any more.


By marinating many times, I found some examples. It sometimes becomes wonderful taste but sometimes becomes too acidic or gets strange pink mold. The acidic one can be eaten by mixing with milk or soy milk and put into spaghetti with bacon. But in case of pink mold, it should be discarded. Considering those cases, I found that tofu should be blanched and drained before marinating. When blanched, some unwanted bacteria may be sterilized. Just make sure you need to cool down tofu under 60°C when marinating because enzyme of koji cannot be active at high temperature. You can enjoy marinated tofu after 7-10 days. Of course, I recommend you to use good quality tofu if you can get it.