Koji rice is a key ingredient in making shio koji paste, a traditional seasoning used in Japanese cuisine.
What is Koji Rice?
Made from steamed rice that has been inoculated with Aspergillus oryzae, a type of mould, this mould is also known as koji-kin and is essential in various Japanese fermentation processes. The mould spores are spread over the rice, which is then incubated in a warm, humid environment to allow it to grow.
The resulting product is rice with a white, fluffy coating of koji mould.
What is the purpose of koji mould?
The enzymes produced by the koji mould, particularly amylase and protease, are critical in the fermentation process. Amylase breaks down starches in the rice into simple sugars, while protease breaks down proteins into amino acids. These enzymatic actions enhance the flavours and nutritional value of the fermented product.
What is Shio Koji Paste?
Shio koji paste is a mixture of koji rice, salt (shio), and water. The mixture is left to ferment, typically for about a week, during which time the enzymes from the koji rice break down the components of the mixture, creating a savory, umami-rich paste. The paste can be used as a marinade, seasoning, or to tenderise meat, fish and vegetables.
How to make shio koji paste at home:
Ingredients:
- 200 grams of koji rice
- 60 grams of salt
- 300 milliliters of water
Method:
- Combine Ingredients: Mix the koji rice, salt, and water in a clean container.
- Fermentation: Cover the container loosely to allow air circulation and let it sit at room temperature.
- Daily Stirring: Stir the mixture once a day to ensure even fermentation and to prevent mould from forming on the surface.
- Completion: After about a week, the mixture should thicken and develop a pleasant, sweet-salty aroma. Once fermented, it can be stored in the refrigerator for several months.
Benefits of Shio Koji Paste
The natural fermentation process enhances flavors, adding a rich umami taste to dishes. Fermented foods like shio koji are known to have probiotic benefits, aiding in digestion and overall gut health.
For inspiration see How to use above.
Store in a cool, dry place away from direct sunlight.