Healthy Spinach Gomaae with Koji (No Sugar Added)

12 minutes ago
3 min read

Chopsticks lift seasoned cooked spinach from a glass bowl over a patterned plate.

A Traditional Japanese Side Dish Made Gut-Friendly with Ama-Koji

Spinach Gomaae (Sesame Spinach Salad) is one of the most iconic side dishes found in Japanese homes.

Growing up in Japan, it was something I saw regularly on the dinner table—simple, nutritious, and loved by both children and adults.

Traditionally, gomaae is seasoned with soy sauce and sugar. While delicious, I rarely use refined sugar in my cooking today. Instead, I use ama-koji and soy sauce-koji to create natural sweetness and deeper umami.

The result is a gentler, more nourishing version of this classic dish that still tastes authentically Japanese.

One thing many people outside Japan may not realize is that Japanese spinach is typically sold with the stems attached, unlike baby spinach commonly found in American grocery stores. The stems provide additional texture and hold up beautifully in traditional gomaae.

RECIPE OVERVIEW |

Prep Time: 10 minutes
Cook Time: 2 minutes
Total Time: 12 minutes
Serving Size: 2 servings
Equipment Needed:
- Small pot
- Mixing bowl
- Ice bath
- Mortar and pestle (or spice grinder)
Difficulty Level: Beginner
Suitable For:
- Vegetarian
- Dairy-Free
- Refined Sugar-Free
- Gut-Friendly

NUTRITION & GUT HEALTH BENEFITS |

Ama-Koji: Natural Sweetness Without Refined Sugar

Ama-koji provides natural sweetness derived from rice fermentation rather than refined sugar. It also contributes beneficial enzymes and additional nutrients.

Soy Sauce-Koji: Extra Umami from Fermentation

soy sauce-koji enhances flavor while allowing you to use less soy sauce. Fermentation develops complex flavors that make simple vegetable dishes much more satisfying.

Spinach + Sesame = Traditional Japanese Wisdom

Spinach contains oxalates, naturally occurring compounds that can interfere with calcium absorption. Sesame seeds are rich in calcium, making this pairing a practical and time-tested combination in Japanese cooking.

Rich in Fiber & Micronutrients

Spinach provides:

Vitamin K
Folate
Iron
Fiber

Sesame seeds provide:

Calcium
Healthy fats
Antioxidants

INGREDIENTS |

200g spinach
2 tbsp toasted white sesame seeds
1 tbsp soy sauce-koji
3 tbsp ama-koji
1 tsp sesame oil

INSTRUCTIONS |

Boil spinach for about 1 minute until just tender.
Transfer immediately to an ice bath.
Cool for less than 1 minute, then squeeze firmly to remove excess water.
Cut into bite-sized pieces.
Grind the toasted sesame seeds until fragrant.
Mix sesame, ama-koji, and soy sauce-koji in a bowl.
Add spinach and toss evenly.
Finish with sesame oil.

RECIPE NOTES |

Cooling spinach quickly helps preserve its vibrant green color.
Japanese spinach with stems attached works best.
Avoid overcooking the spinach.
Freshly ground sesame seeds create significantly better flavor than pre-ground sesame.

SERVING SUGGESTIONS |

Serve alongside:

Grilled fish
Miso soup
Rice
Pickles

Together, these dishes create a traditional Japanese-style meal often referred to as "Ichiju Sansai" (one soup, three dishes).

SHOPPING TIPS |

AMA (SWEET) KOJI:

A white Hakkaisan amazake bottle with Japanese text sits on a light-colored table. Background features white subway tiles.

Ama koji is rarely available as a standalone product in stores. I always recommend making it at home if possible, since it is simple and contains only rice koji and water.

👉 How to Make Ama Koji

If you prefer a ready-made option, Hakkaisan’s Koji Amazake is very close to homemade ama koji. It uses only high-quality koji and water, without added sugar or unnecessary ingredients. You can often find it at Japanese grocery stores.

Choose the simplest ingredient list possible — quality matters.

SOY SAUCE KOJI:

Making Your Own Soy Sauce Koji at Home is the Best Option:

Homemade soy sauce koji using high-quality soy sauce and rice koji allows you to avoid preservatives. The flavor is noticeably more balanced when made fresh.

👉 How to Make Soy Sauce Koji

However, if you don't have time to make your own or can't find fresh soy sauce koji in the refrigerated section of your local Japanese market, this Oryzae product is a convenient alternative.

A rich, umami-packed seasoning made by fermenting koji with soy sauce. Use it as a finishing sauce, marinade, dipping sauce, or flavor booster for rice bowls, roasted vegetables, eggs, meat, seafood, and tofu.

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JAPANESE MORTAR & PESTLE (Suribachi & Surikogi)

Brown ceramic mortar and pestle on a white background, angled to show the ribbed interior and pale pestle handle

A Japanese mortar and pestle — called suribachi (mortar) and surikogi (wooden pestle) — is an essential tool in traditional Japanese kitchens.

Unlike Western smooth mortars, the inside of a suribachi has fine ridges that help grind ingredients more efficiently.

I especially love using it for freshly ground sesame seeds. When sesame is ground just before serving, the aroma and flavor are completely different — richer, nuttier, and more vibrant.