Whenever I find incredible, fresh eggs at the farmers’ market, it immediately inspires me to make homemade mayonnaise. Ever since I started incorporating shio koji into my kitchen, it has become my absolute favorite way to make it.
This isn’t just a condiment; it’s a living, wellness-forward food. The raw shio koji provides a beautiful, deep umami flavor that elevates the mayonnaise, while also packing it with active enzymes and probiotics. It’s so easy to make and so deeply flavorful that you may never go back to store-bought mayonnaise again.
Ingredients of Koji Mayonnaise
- Taihaku sesame oil, rice oil, or avocado oil: 150ml
- Egg: 1 whole (room temperature or pasteurized)
- Shio koji: 2 tablespoons
- Rice Vinegar: 1 tablespoon
- Lemon juice: 1/2 tablespoon
- Dijon mustard: 1 teaspoon
Step-by-step of Koji Mayonnaise
Combine the Base: In a tall, narrow container (like a beaker or deli cup), add the room-temperature egg, shio koji, rice vinegar, lemon juice, and Dijon mustard.
Add the Oil: Gently pour the 150ml of your chosen oil directly on top. Allow it to sit for a moment so the oil floats and the egg remains pooled at the bottom.
Blend: Plunge an immersion blender all the way to the bottom of the container, directly over the egg. Turn it on high and keep it completely still against the bottom for 10–15 seconds until the mixture turns opaque and thickens around the blades.
Emulsify: Slowly tilt and pull the blender upwards to draw the remaining oil down. Continue blending until the mayonnaise is perfectly uniform, thick, and creamy.
Choosing the Right Oil
The main ingredient in mayonnaise is oil, so choosing a high-quality one is essential for both flavor and wellness. I normally use Taihaku (white) sesame oil or rice oil, but I also love avocado oil and perilla oil. They have very neutral flavors and offer excellent health benefits, such as omega-3 fatty acids.
I recommend steering clear of extra-virgin olive oil, which has a very strong, bitter flavor that can overpower the delicate koji, as well as highly processed industrial seed oils like canola, grapeseed, safflower, and peanut oil.
A Note on Active Enzymes (And How to Use It)
Because this mayonnaise uses raw shio koji, it is full of active amylase enzymes. This is incredible for your gut health, but it means you need to be mindful of how you use it.
Amylase breaks down complex carbohydrates into simple sugars. If you use this raw koji mayonnaise to dress a potato salad or a harusame (glass noodle) salad and let it sit in the fridge, the enzymes will break down the starches, turning your salad watery and unpleasantly sweet.
How to enjoy it: Skip the starchy make-ahead salads! Instead, use this as a rich, umami-packed dip for crisp, raw vegetables, a luxurious spread for sandwiches, or a finishing sauce for grilled fish and meats.
Is the Raw Egg a Concern?
I am personally not concerned about using a raw egg in this mayonnaise, but this is always a personal choice. If you are concerned about salmonella, you can certainly use a pasteurized egg. If you want to learn more, I recommend reading up on current food safety guidelines regarding raw eggs to make the best decision for your household.
Japanese Koji Mayonnaise
Equipment
- Immersion blender
- Tall, narrow container
Ingredients
- 10 tbsp Taihaku sesame oil or rice oil
- 1 pc whole Egg room temperature or pasteurized
- 2 tbsp Shio koji
- 1 tbsp Rice vinegar
- 1/2 tbsp Lemon juice
- 1 tsp Dijon mustard
Instructions
- Combine the Base: In a tall, narrow container, add the room-temperature egg, shio koji, rice vinegar, lemon juice, and Dijon mustard.
- Add the Oil: Gently pour the 150ml of your chosen oil directly on top. Allow it to sit for a moment so the oil floats and the egg remains pooled at the bottom.
- Blend: Plunge the immersion blender all the way to the bottom of the container, directly over the egg. Turn it on high and keep it completely still against the bottom for 10–15 seconds until the mixture turns opaque and thickens around the blades.
- Emulsify : Slowly tilt and pull the blender upwards to draw the remaining oil down into the vortex. Continue blending until the mayonnaise is perfectly uniform, thick, and creamy.
