Premium Polished Sweet Rice Koji (250g)

Polished Rice Koji for Sake, Amazake, Mirin, Amakoji, and Your Best Ferments Yet.

This premium rice koji is made using heirloom spores—prized for their enzymatic strength and transformative power—from Higuchi Matsunosuke Shoten in Osaka, Japan, and carefully cultivated on polished Calrose rice from southern California.

All koji is made by hand at Virginia’s first and only sake brewery - North American Sake - in Charlottesville, VA.

 Explore New Flavors and Techniques 

We designed this rice koji specifically to help you:

• Brew your best sake and mirin
• Ferment one-of-a-kind amazakes
• Experiment with sakadane, amakoji, and more!

 What does "polished" mean? 

In sake brewing, rice is polished to remove the outer layers of the grain that can produce bitter flavors. This process is measured by the Rice Polishing Ratio (RPR) — the lower the RPR, the higher the sake quality. While most sake uses 70–90% RPR, the rice used to make this koji is 50% RPR, and is the same used to brew junmai daiginjo sake — the highest quality of sake. This process yields a koji that brings the purest sweetness to any recipe.

We believe that well-made koji isn’t just an ingredient. It’s a tool for flavor innovation and a portal to both the deep past and culinary future. Trusted by fermentation wizards, home cooks, and Michelin-star chefs alike, koji is the backbone of Japanese fermentation—and this one’s made to be yours.

Ingredients: Aspergillus oryzae: Hi-G koji kin (Osaka, Japan), 50% polished short grain Calrose rice (California, US)

All koji is frozen immediately, then dried in small batches to ensure freshness and maximum enzymatic potency.