Ama Koji – The Sugar Alternative That’s Naturally Sweet & Gut-Friendly
- Aug 9, 2025
- 3 min read
Updated: Feb 19
CONTENTS
ABOUT THIS RECIPE | WHAT IS "AMA KOJI"?
Ama Koji (甘麹) is a naturally sweet fermented paste made from just rice koji and water—no added
sugar! Thanks to the enzymatic power of rice koji, the natural starches in the rice are broken down into simple sugars during fermentation, creating a mild, gentle sweetness. This traditional Japanese sweetener is a versatile, gut-friendly alternative to sugar that supports your health while adding flavor and depth to both sweet and savory recipes.
GUT HEALTH BENEFITS |
Rich in enzymes that help break down food and support better digestion
Naturally sweet without added sugar, making it a great alternative for those watching their blood sugar
Contains prebiotics that nourish the good bacteria in your gut
May support energy levels, immune health, and skin health due to its gentle fermentation process
Completely additive-free, gluten-free, and vegan
INGREDIENTS | (Makes about 550ml)
200g dried rice koji
350ml warm water (~60°C / 140°F)
SHOPPING TIPS |
Miyako RICE KOJI:
UPDATED on 2/19/2026:
I recently found this dried koji (made in Japan) on Amazon, and it has become my new go-to for homemade miso and all of my koji-based seasonings.
This brand is more cost-effective while still maintaining excellent quality. The grains are consistent, the fermentation is stable, and the flavor develops beautifully — especially for miso, salt koji, soy sauce koji, and amazake. Good koji is the foundation of everything. If your koji is high quality, your final product will naturally taste more balanced and deeply umami-rich.
This is the one I personally use now in my kitchen.
Oryzae RICE KOJI:
UPDATED on 2/19/2026:
This is another excellent dried koji option available on Amazon, also made in Japan.
It is slightly more expensive than my current go-to brand, but the quality is very good. If my primary choice isn’t available, this is the one I purchase.
One thing I always tell my students: try a few different koji brands. Just like wine or miso, there are subtle differences in aroma, sweetness, and enzymatic strength. Over time, you’ll find the one that fits your preference and cooking style. Quality koji truly makes a difference.
Other RICE KOJI:
Look for dried rice koji at Japanese or Asian grocery stores in the refrigerated section. Brands like Cold Mountain, Marukome, or Hikari are reliable. Japanese supermarkets like Nijiya, Mitsuwa, Marukai often carry a few different kinds of KOJI.
INSTRUCTIONS |
Sterilize your tools: Place all utensils and containers in boiling water for at least 8 minutes. Use only heat-resistant, BPA-free glass or plastic. Let air dry completely.
In a sterilized container, combine the rice koji and warm water.
Mix gently to fully moisten the koji.
Keep the mixture at a consistent 55–60°C (131–140°F) using a yogurt maker, sous vide (my recommendation: Anova Sous Vide Precision Cooker 3.0), rice cooker on “keep warm,” or other low-temp setup for 6-8 hours. The key is the temperature control!
Once fermentation is complete, blend with a hand blender or regular blender for a smoother consistency (optional).
Cool and Store: Let it cool, then transfer to a clean jar. Store in the fridge up to 7 days.
HOW TO USE AMA KOJI |
Stir into plain yogurt or plant-based yogurt
Add a spoonful to lattes, smoothies, or tea
Use in dressings, marinades, or sauces for natural sweetness
Replace sugar in baking recipes like muffins or pancakes
Drizzle over fruit, oatmeal, or rice porridge
FINAL THOUGHTS |
Ama Koji is a beautiful example of how traditional Japanese fermentation can offer both flavor and wellness benefits. With its natural sweetness, enzyme power, and gut-friendly properties, it’s an excellent replacement for refined sugar—perfect for anyone looking to reduce sugar while still enjoying sweet flavors.
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