Some Japanese sauces and marinades should be a staple in your pantry if you enjoy cooking Japanese food. Soy sauce, rice wine vinegar, and mirin are a few of the standard and familiar ingredients used in Japanese cuisine. But there is a lesser-known but no less flavorful ingredient that many Japanese chefs consider a secret weapon in crafting savory umami flavors.
It’s koji. Its use is to add intense flavor to some of your favorite ingredients, such as miso and soy sauce. You can also use it to develop complex marinades that add fantastic taste to many proteins and vegetables.
What is Koji?
Koji, in its base form, is a mold spore (Aspergillus oryzae). And when it is cultivated on grains such as rice, the magic starts. It is rice koji that many Japanese chefs use to make many amazing ingredients and dishes, including shio koji, a mouthwatering marinade brimming with umami.
And, you don’t need to travel to Japan or locate a high-end Japanese restaurant to sample this delectable creation — you can easily make it yourself at home! The first step is obtaining rice koji.
What is Rice Koji?
Koji rice is a type of fermented rice that has already been inoculated with the Aspergillus oryzae mold spores. The mold has fermented the rice by breaking down the proteins and carbohydrates. Although it can appear a little off-putting, it’s the secret ingredient for making several Japanese food that you might already have in your pantry.
As the rice ferments, the carbohydrates and proteins are turned into amino acids and sugars that lend immense umami flavor to whatever dish, drink, dessert, or sauce. Rice koji is primarily used as a starter for fermented food products, helping to create mirin, sake, miso, among many other foods. You can also use it to make shio koji, a deliciously sweet, funky marinade.
What is Shio Koji?
In English, shio koji means salt mold, and while this thick, lumpy, moldy paste doesn’t look very appetizing, there is no denying the big flavors it delivers. Many Japanese chefs today use it as an all-purpose seasoning or to tenderize meats and fish. Creative chefs have even used it in pasta dishes, and you can use it to enhance salads, vegetables, and even baked goods.
And because shio koji is a fermented food, it is also relatively healthy. You can use it as a low-sodium alternative to soy sauce.
How to Make Shio Koji from Rice Koji
Without an Asian or Japanese grocery nearby, it might be pretty hard to find shio koji. However, you can easily order rice koji online and make your shio koji!
We suggest using rice koji from Marukua, a high-quality, organic malted rice that has been specially crafted and contains no sugar or additives.
Once you have your rice koji, follow these simple instructions. You’ll soon have fantastic shio koji to experiment within the kitchen, and produce intensely flavorful dishes.
- Mix 200 grams of rice koji with 60 grams of salt. Then add 250 – 450 cc of water and mix thoroughly.
- Place the mixture into a container and leave the lid open a small bit. This will allow the gases that are produced during the fermentation process to escape.
- Depending on the climate conditions, the mixture must sit a specific number of days to ferment properly. Let it sit at room temperature for seven days in summer and ten days in winter. Stir once every two to three days. If you need to stop the fermenting process for some reason, place the shio koji in the fridge with an airtight lid.
- Once the shio koji has finished fermenting, and you are free to enjoy it in many versatile ways. It is recommended that the shio koji be consumed within six months.
How to Use Shio Koji
The most common use for shio koji is as a marinade for proteins. Select the beef, poultry, or fish you plan to cook. Then, spread the shio koji over the protein, allowing it to marinate for 12-24 hours. This will help to tenderize the protein and boost the flavor.
You can also mix it with sauces, salad dressings, baked goods, and more to develop rich, distinctive flavors. Or you can simply use it in place of salt — two teaspoons of shio koji can replace one teaspoon of salt, and it will be a lot tastier too!
Add shio koji to noodle dishes such as soba, ramen or udon, or simmer vegetables in dashi with a bit of shio koji added to the dashi broth. The possibilities are endless!