TEA FACTORY GEN
Hiroshima Zairai Koji Fermented Black Tea - Made with Sake Koji and Native Tea Leaves Craft Tea by TEA FACTORY GEN 0.70 oz/20g
Hiroshima Zairai Koji Fermented Black Tea - Made with Sake Koji and Native Tea Leaves Craft Tea by TEA FACTORY GEN 0.70 oz/20g
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Grown from seed and nurtured for 60–70 years, these deep-rooted tea trees draw mineral-rich nutrients from over 2 meters underground—creating a naturally sweet, clean, and refreshing flavor.
Unlike standard “oxidation-based” black tea, this one is fermented with traditional tane-koji used in sake brewing—honoring centuries of Japanese fermentation culture while creating a completely original, smooth, umami-rich tea.
Because it’s grown without fertilizers, the tea avoids the heavy umami of gyokuro and instead expresses the leaf’s natural sweetness and the wild vitality of the land.
Since its founding in 1972, TEA FACTORY GEN is a tea atelier based in the Sera Highlands of Hiroshima, Japan.
They honor nature and tradition, producing tea through a fully integrated process using no chemical fertilizers or pesticides.
How to Use
To maintain the proper temperature, pre-warm your teaware before brewing.
Use 2g of tea leaves per 100ml of boiling water. Steep in a teapot for 3 minutes.
For a second infusion, also use boiling water and steep for at least 3 minutes.
More Info
Hiroshima Native (Zairai) Tea: "Native tea" is tea planted and grown from seeds, and is a valuable category that makes up only about 3% of all tea in circulation. These tea trees are 60–70 years old, with roots extending over 2 meters deep into mineral-rich soil. Because they are grown without fertilizers or pesticides, they may lack the dense umami of gyokuro, but instead offer something more essential: natural sweetness, a clean and refreshing flavor, and the pure vitality of the land.
Rarity No.1 — Hiroshima Indigenous Koji-Fermented Black Tea: Crafted from long-standing tea trees in Sera Town (Hiroshima Prefecture), this black tea is uniquely fermented using tane-koji, a traditional starter used in sake brewing. While black tea is typically formed through oxidation, the makers sought a tea that truly undergoes fermentation. By applying Japan’s ancient koji culture—older than tea itself—they created an original tea found nowhere else in the world. Encountering the power of koji, which has an even longer history than tea itself, deeply moved them. The invisible collaboration between microorganisms and tea leaves brought forth a flavor unlike anything they had ever experienced.
Flavor & Wellness: This fermented black tea has a rich depth reminiscent of sake or amazake, with a smooth, gentle mouthfeel. Highly nutritious, it’s especially recommended for those who value wellness and health. Its aroma blends the natural fragrance of tea leaves with mellow umami produced through fermentation, resulting in a flavor that is both distinctive and warmly inviting.
A One-of-a-Kind Tea Experience: By honoring the historical legacy of koji while aligning with modern tastes, this tea harmonizes tradition and innovation. They invite you to discover this truly unique fermented black tea—an experience unlike any tea you've had before.
Details
Naturally Grown Hiroshima Zairai Koji-Fermented Black Tea
Tea (from Hiroshima), Koji Mold
20g (0.70oz)
360 days
(Contact us if you'd like to know more.)
Chemical fertilizers-free
Herbicides-free
Chemical pesticide-free
Allergy-free
Store in a cool, dry place away from direct sunlight.
