Below is my best interpretation of a simple recipe for making Japanese mayo. After scrounging around the internet and doing some home test cooking this is the simplest recipe that I think best captures the flavor of a store bought Japanese mayo brand such as Kewpie. Anyone who says there recipe is the same as Kewpie's is lying, but at least we can get close.
If you have never made mayonnaise at home before I highly recommend it. The emulsion of the egg, oil, and vinegar reminds me of a high school chemistry lesson, and it is deeply satisfying to make something that you often just eat out of a jar.
Feel free to substitute this homemade Japanese mayo in for store bought mayo for any of the other mayo inspired recipes on this website.
1 Egg Yolk
1/2 Cup Vegetable Oil ( or other Neutral tasting oil)
1 Tbsp. Apple Cider Vinegar
1/4 Tsp. MSG
1/2 Tsp. Mustard Powder
1/8 Tsp. Salt
1/2 Tsp. Sugar
2 Tsp. Lemon Juice (Half of a lemon)
1. Mix egg yolk, vinegar, MSG, mustard, salt, sugar, and lemon juice in a narrow cup or bowl with an immersion blender or regular blender
2. Slowly pour in oil into the egg/vinegar mixture while mixing with the immersion blender or regular blender. This is the emulsion process turning the oil into millions of tiny droplets. This is very difficult to accomplish with a whisk, but possible with enough time and elbow grease.
3. Chill and serve. Lasts for up to one week.