Sake Yeast & Koji

Sake Yeast and Koji for Home Sake Brewing

Sake depends on two jobs happening together: koji converts rice starch into fermentable sugar while sake yeast turns that sugar into alcohol, aroma, and structure. This collection brings together the yeast and koji options home sake makers use to build a clean, organized fermentation.

Use this page when you are choosing between #7 and #9 sake yeast, deciding whether to start with prepared yellow koji rice or koji-kin spores, or adding yeast shipping protection for warm-weather liquid yeast orders.

Choosing Sake Yeast: #7 vs #9

• Sake #7 yeast: a good choice for a clean, balanced sake profile with dependable fermentation character.
• Sake #9 yeast: often chosen when the goal is a more aromatic, fruit-forward, Ginjo-leaning profile.
• Liquid yeast handling: liquid sake yeast should be treated as temperature-sensitive. For shipped orders, consider insulated packaging and ice packs, especially during warm weather.

Koji, Koji-Kin, and Rice Conversion

Koji is essential because rice starch is not directly fermentable by sake yeast. Prepared yellow koji rice is the simpler path because the koji has already been grown. Koji-kin gives hands-on brewers the spores needed to propagate koji on steamed rice, but it requires more process control and sanitation discipline.

Build the Rest of Your Sake Batch

If you are planning a complete batch, pair your yeast and koji choices with sake rice, sake recipe kits, sake making equipment, and the main sake making supplies hub. For a process overview, read the beginner guide to making sake at home.

Sake Yeast and Koji FAQ

Do I need both sake yeast and koji?

Yes. Koji helps convert rice starch into sugar, while sake yeast ferments that sugar into alcohol and produces the fermentation profile.

What is the difference between koji and koji-kin?

Koji is rice that has already been grown with koji mold. Koji-kin is the spore culture used to make koji from steamed rice.

Should beginners use #7 or #9 sake yeast?

#7 is a strong starting point for a clean, balanced profile. #9 is useful when you want a more aromatic, fruit-forward sake character.

Should liquid sake yeast ship with ice?

Liquid yeast is temperature-sensitive. Insulated packaging and ice packs are recommended during warm weather, though carrier heat exposure can still affect yeast in transit.