This week we’ll share a series of articles inspired by our Fermentation 2.0 Workshop at the Cookbook Store last week. We started the evening by promising that we’d answer all the questions that we could but that we were likely to get stumped by some of the questions and would answer them on the blog in the coming days.
Similar to our article on Natto, this article will be a high-level overview of Koji (which is steamed rice/ barley that is injected with mold spores and fermented). Much like Natto, we didn’t know of it and promised to find out more!
What is Koji?
In short, we’re talking about mold. A sweet fragrant mold that’s often used to make pickles, beverages or other ferments. The scientific name for the mold is Aspergillus Oryzae (I have no idea how to pronounce it so don’t feel bad if you don’t either!)
Koji is often associated with the production of Sake (a common type of rice wine) but is also introduced to other ferments including miso, soy sauce, rice vinegar, mirin, amazake, and pickles. Unlike Koji it’s fragrance is often celebrated – it is pleasant and sweet. You can make it, buy dried or whole versions. It can be expensive; 10 grams (0.02 pounds) of koji kin (to make sake) sells for $13! A little goes a long way – those 10 grams are enough to make 22 liters (about the same number of quarts) of sake.
I’ve never noticed it for sale at Farmers Markets but you can buy Koji (and starter to make your own) online. I also haven’t seen it for sale in stores and can only suggest asking Ontario Sake if they would sell any (they are a Sake maker located in the Distillery district; they don’t mention selling it on their website but may be worth a call).
Sandor Katz (also known as ‘Sandorkraut’ though I like to think of him as ‘The Krautfather’) recommends GEM Cultures for buying Koji starter online. They will ship Internationally and their prices seem to be very fair.
Key Steps of Making Koji
- Starter. Although it’s possible to create your own Koji starter (Sandor Katz explains that he’s made it from corn husks) though you’re best to leave this until you’ve gained experience in making Koji and recognizing its unique smell.
- Inoculate. Stirring in the starter. You want to make sure that the rice or barley has cooled before doing so (or you could kill the mold that you’re trying to create).
- Incubate. Incubation has two phases; the first is keeping it warm enough to incubate but, as the mold develops, it will generate its own heat and the challenge becomes preventing overheating.
How to make Koji
Here’s a 10,000 foot overview of how to make Koji:
- Soak rice/barley
- Incubate (for 36 to 48 hours). 80 to 95 degrees. Higher temperatures convert starch to sugars (Koji made at these temperatures tend to be sweeter and used in beverages) while lower temperatures which digest proteins (often used for miso).
There is no better primer for making Koji than The Art of Fermentaion; much of Sandor’s detailed walkthrough of making Koji can be previewed online (for free) here.
Have we missed anything you were hoping for in this primer? I’d love to know…