Day 1 of kankoji in mason jar.

A few weeks ago, I was intrigued by a post to /r/koji on reddit asking if anyone had ever made “kankoji” before.

I was immediately intrigued and went searching for the Instagram post in question. I found the post in question from @mizunomichi_2020:

While the poster wasn’t particularly forthcoming with a recipe, they did explain that it is made from koji rice, cooked glutinous rice, and salt. From this I surmised that this is what I might call a “rice miso”. That is, the main protein source is rice instead of soy beans or some other protein-rich substance.

So, let’s make it!

9/27—Day 1

I’m following a simple and fairly standard method of 1:1 rice koji to protein source by weight with 10% salt, which should give us a fairly long-lasting ferment.

  • 500g koji rice (fridge-dried)
  • 500g cooked glutinous rice
  • 100g salt

I soaked 250g glutinous rice overnight, then cooked in a rice cooker (with about 400mL water, according to the “knuckle test”). I ended up with 700g, so I ate 200g as a snack.

The koji rice and cooked rice were mixed as best as I could (I should have also added the salt here but forgot). To get the smooth paste look like the Instagram post, I decided to put it through the meat grinder attachment of my stand mixer. I still did not quite achieve the smooth texture of the photo, but that may come with time as the koji rice grains break down.

About 80g of the total mixture was lost to the grinding process, but it was so thick and sticky that I added that back in as water to loosen it up a little. I also remembered the salt and added that in, mixing with a rice paddle.

This all fit a little too perfectly in a 1L mason jar, so I was able to use a lid weight technique I learned from Koji Alchemy. After salting the top surface, a regular-mouth lid and ring inside a plastic bag are placed on top and the outer jar lid is screwed on loosely but enough to push the inner lid down very slightly like a weight.

I’m interested to see if I get any tamari from this. Check back in a few weeks!