Onion Koji

 
 
 
 
 

Onion koji is the most popular modern koji seasoning in Japan right now. In fact, most Japanese customers who buy koji from us are making their own onion koji. In other words, it’s a magical seasoning to make everything yum! The flavor’s like caramelized onions without cooking or chicken stock without chicken.

<3 reasons why onion koji is so popular >
1. easy to make steps
2. no artificial flavors or preservatives
3. makes delicious and nutritious meals easily (more umami and flavor than shio koji simply by adding onion)

There are so many onion koji recipes in Japan. While the main ingredients are the same: koji, onions and salt, the variations are numerous, including: Ratio of ingredients, fermentation process (keeping at room temp or warmed up), onion texture (chunky or smooth), koji texture (chunky or smooth), etc. We'll share 2 recipes: the first recipe is one of the more common recipes, and the 2nd one is an alternative way of using shio koji. The 2nd one is faster than making it with koji from scratch as the koji in shio koji has already been fermented. Yuri often uses the 2nd recipe for its convenience.

Please try out some different recipes and use them for your regular cooking. It’s a great way to find out your best recipe!

 
 

Type-A (COMMON)

 

INGREDIENTS

Koji: 70 gram
Onions: 200 gram
Salt: 25 gram

 

DIRECTIONS

  1. Peel off the onions' skin and cut them roughly into small sections so they can be blended by a food processor.

  2. Blend onions in the food processor.

  3. Put the blended onions, koji and salt into a clean glass jar.

  4. Keep it at room temperature for about 1 - 2 weeks until the desired flavor comes out. Or keep in an Instant Pot or yogurt maker around 60 C (140 F) for about 6 - 8 hours.

Additional Suggestions

  • After the onion koji is ready to use, store it in the fridge or freezer.

  • If you prefer a smooth texture for the koji, you can blend it with onions. But not at the same time; it’s better to add koji after the onion is blended and liquidy.

  • This recipe uses less salt than our own shio-koji. If you cook dishes with our recipe using shio-koji, you may want to add a little extra salt to balance things out better.

 

Type-B (Alternative STYLE)

INGREDIENTS

JORINJI Shio-koji: 255 gram (9 oz)
Onions: 255 gram (9 oz)
Salt: 36 gram (Approx. 1/7 of Onions’ Weight)

 

DIRECTIONS

  1. Peel off the onions’ skin and cut them roughly into sections.

  2. Put all ingredients into a clean container (or a wide mouth glass jar) and blend them with a handy blender.

  3. Keep it at room temperature for 3 days - 1 week until the desired flavor comes out.

Additional Suggestions

  • If you want to use the onion koji immediately, then you can use it soon after blending. The flavor profile will be a bit lower, but it may work because the koji has been fermented already .

  • Usually onion koji contains no water, but this recipe does because shio-koji contains water. If you prefer more onion flavor, then use the more common recipe above.

  • This recipe’s sodium content is almost the same as our shio-koji. This means you can use our shio-koji and onion koji interchangeably, depending upon your needs.

 

HOW TO USE ONION KOJI?

  • You can use onion koji as salt substitute. First, use about 8% of the onion koji based on the weight of the dish, then adjust accordingly.

  • As the onion koji still has active enzymes, if you add it into warm food (like steamed potatoes), it’ll break them down and end up becoming a liquid mush. To avoid this, heat up onion koji to 160F on the stove top or microwave it in advance.

 

THE RECIPES OF THE SAMPLES FOR PORTLAND FERMENTATION FESTIVAL 2024

1) POTATO SOUP

INGREDIENTS

Potatoes: 1 lb
Water: 1.8 lbs (about 800 gram)
Onion Koji (Type-B): 4 tablespoons

 

DIRECTIONS

  1. Peel off the potatoes’ skin and cut them roughly into sections.

  2. Place the potatoes in a pot and add water, cook it until the potatoes become soft.

  3. Blend it with a handy blender.

  4. Add onion koji.

2) CHICKEN NUGGETS

INGREDIENTS

Ground Chicken: 1 lb
Onion Koji (Type-B): 2- 3 tablespoons

 

DIRECTIONS

  1. Add chicken and onion koji in a bowl and mix until the onion koji is absorbed into the chicken.

  2. Pre-heat oven at about 450 F.

  3. Scoop the chicken and place it on a baking pan (or on a baking sheet on the pan).

  4. Bake it for about 15 minutes until the surface is browned.

Shio-Koji, KojiYuri Migaki