Naturally Brewed in Wakayama, Japan
Experience one of Japan’s rarest traditionally brewed soy sauces; naturally fermented for two years in historical wooden barrels using whole Marudaizu soybeans, sun-dried salt, traditional Koji fermentation, and sacred mineral-rich water from Mount Koya.
Crafted in limited quantities by Kaneiwa Shoyu, Koshiki Shoyu is an authentic Koikuchi soy sauce created for chefs, collectors, and those who understand the difference between industrial seasoning and true fermentation craftsmanship.
THE SOUL OF TRADITIONAL JAPANESE SOY SAUCE
Most soy sauce today is engineered for efficiency.
Koshiki Shoyu is engineered by time.
Produced by Kaneiwa Shoyu in Wakayama, Japan; historically regarded as the birthplace of Japanese soy sauce brewing; this exceptional Koikuchi shoyu is naturally brewed and matured for two full years inside traditional wooden barrels using methods preserved across generations.
This is not modern industrial soy sauce.
This is living fermentation.
WHY KOSHIKI SHOYU IS DIFFERENT
Crafted the Traditional Way; Because Flavor Cannot Be Rushed
Unlike mass-market soy sauces fermented rapidly in stainless steel tanks, Koshiki Shoyu is slowly matured inside living Kioke wooden barrels where native microorganisms develop extraordinary depth and complexity over time.
What Makes Kaneiwa Exceptional
- Naturally aged for 2 years in traditional wooden barrels
- Made using 100% whole Marudaizu soybeans
- Naturally fermented using traditional Koji culture
- Brewed with sacred mineral-rich “Kukai Water”
- Crafted in Wakayama, Japan
- Produced in limited quantities
- No preservatives
- No artificial flavouring
- No MSG
This is the kind of soy sauce chefs use sparingly; because a few drops are enough to transform an entire dish.
SACRED WATER; THE SOUL OF KANEIWA
The Water That Defines Everything
Kaneiwa Shoyu is the only brewery in Japan known to brew using “Kukai Water” (空海水) a sacred underground spring believed to have been discovered by Kukai, founder of Shingon Buddhism.
Flowing through the forests of Mount Koya, this exceptionally pure mineral-balanced water forms the foundation of every batch.
Why It Matters
- Water makes up over 50% of soy sauce
- Mineral composition directly influences fermentation
- Purity shapes aroma, clarity, texture, and depth
This is not simply an ingredient.
It is the soul of Kaneiwa.
THE IMPORTANCE OF MARUDAIZU WHOLE SOYBEANS
Most commercial soy sauce uses defatted soy remnants.
Koshiki Shoyu uses whole Marudaizu soybeans.
Why this matters:
- Higher protein content
- Greater amino acid development
- Deeper natural umami
- More elegant texture
- Richer fermentation complexity
Whole soybeans are significantly more expensive and far more difficult to ferment consistently; but they produce superior flavour impossible to replicate through shortcuts.
Kaneiwa chooses craftsmanship over convenience.
WOODEN BARREL FERMENTATION (KI-O-KE)
Fermented Inside Living Barrels
Koshiki Shoyu is matured inside traditional Kioke wooden barrels; a centuries-old method now considered extremely rare in Japan.
Unlike stainless steel tanks, wooden barrels:
- Allow natural airflow
- House living microbial ecosystems
- Develop layered complexity over time
- Create softer, more rounded fermentation character
Each barrel carries its own microbial identity, making every batch subtly unique.
This is flavour you cannot industrialize.
KOJI FERMENTATION; THE INVISIBLE CRAFT
At the heart of Kaneiwa Shoyu lies traditional Koji fermentation using Aspergillus oryzae.
During fermentation, enzymes slowly break down proteins and starches into:
- Amino acids
- Natural sugars
- Umami-rich compounds
This slow biological transformation creates:
- Greater depth
- Better mouthfeel
- Natural sweetness
- Long lingering umami
Fermentation is not manufacturing.
It is cultivation.
A SOMMELIER’S PERSPECTIVE
Tasting Notes
Aroma
Roasted soy
Subtle caramel
Aged wood
Deep fermentation character
Taste
Rich layered umami
Balanced salinity
Elegant natural sweetness
Finish
Long
Clean
Complex
Refined
Compared to ordinary soy sauce, Koshiki Shoyu delivers significantly greater aromatic depth and smoother texture while preserving the character of authentic old-style Japanese soy sauce.
HOW TO USE KOSHIKI SHOYU
Use Less. Experience More.
Koshiki Shoyu is best used as a finishing ingredient rather than simply seasoning.
Ideal with:
- Sushi & sashimi
- Grilled meats
- Steamed rice
- Ramen
- Eggs
- Tofu
- Minimalist Japanese dishes
Its depth, aroma, and balanced salinity make it particularly exceptional with premium proteins and raw preparations.
A few drops are enough.
PRODUCED IN LIMITED QUANTITIES
Crafted Slowly. Produced Rarely.
Koshiki Shoyu cannot be industrialized.
Its flavour depends on:
- Time
- Climate
- Natural microbial ecosystems
- Wooden barrel maturation
- Human intuition and experience
Each batch requires years of care and constant monitoring from skilled brewers who evaluate fermentation through aroma, temperature, texture, and taste.
This is not mass production.
It is preservation.
PRODUCT SPECIFICATIONS
Product Name: Kaneiwa Koshiki Shoyu
Type: Koikuchi Shoyu (Dark Soy Sauce)
Style: Naturally Brewed
Aging: 2 Years
Fermentation: Traditional Wooden Barrel Aged (Kioke)
Ingredients: Water, Whole Soybeans, Wheat, Salt
Origin: Wakayama, Japan
Storage: Refrigerate after opening
AUTHENTIC JAPANESE WOODEN BARREL AGED SOY SAUCE
Kaneiwa Koshiki Shoyu is a premium naturally brewed Japanese soy sauce aged for two years in traditional wooden barrels. Made in Wakayama, Japan using whole soybeans, Koji fermentation, and sacred mineral-rich water, this artisanal Koikuchi shoyu delivers exceptional umami depth, aroma, and complexity.
Perfect for sushi, sashimi, steak, rice, fine dining, and Japanese cuisine.
ONCE YOU TASTE REAL SOY SAUCE, THERE’S NO GOING BACK.
Crafted with time, water, wood, and soul.
