Free Traditional Shoyu Moromi Calculator
Formulate authentic Japanese artisanal soy sauce. Balance whole soybeans, cracked roasted wheat, moromi salt brine salinity (18-20%), and paddling schedules.
🍶 Shoyu Style & Raw Grain Batch
Soybeans must be soaked and pressure-steamed until squishable between thumb and pinky finger. Cracked wheat is dry-roasted until fragrant, then blended 1:1 and inoculated with shoyu koji spores for 48 hours at 28°C-30°C before brining.
Roasted Cracked Wheat: 2.00 kg (1:1 Ratio)
• Month 1: Stir daily to aerate halophilic yeast and submerge koji cap.
• Months 2 to 6: Stir once weekly as proteolytic enzymes liquefy grain proteins into amino acid umami.
The Salt Barrier: Shoyu relies on an 18-20% salt barrier. Under 16% salt, putrefactive bacteria take over and spoil the mash; above 22% salt, friendly halophilic yeasts (*Zygosaccharomyces rouxii*) are paralyzed.
Recommended Tools & Equipment
Tested hardware and components for high reliability
Biochemistry of Traditional Honjozo Shoyu
Unlike chemically hydrolyzed soy sauce made with hydrochloric acid in 48 hours, traditional Japanese shoyu is a two-stage microbial masterpiece:
- Stage 1 (Solid-State Koji Cultivation): Fungal mold Aspergillus oryzae secretes abundant neutral and acid proteases, peptidases, and amylases across steamed soybeans and roasted cracked wheat over 48 hours.
- Stage 2 (Liquid Moromi Mash Aging): The koji is plunged into cold 19% salt brine. Over 6 to 18 months, proteases cleave soy proteins into savory monosodium glutamate and amino acids, while wheat starches ferment into subtle alcohol and fragrant esters.
Brine Formulation Equations
Total Dry Grain: M_grain = M_soy + M_wheat
Water Volume: V_water = M_grain × Hydration_Ratio (Liters)
Salt Mass (g): M_salt = (V_water × 1000 × Salinity_Pct) / (100 - Salinity_Pct)
Frequently Asked Questions
Why is wheat roasted and cracked rather than boiled?
Roasting wheat until golden brown toasts wheat starches (Maillard browning) into maltol, vanillin, and sweet aromatic esters that give Japanese soy sauce its signature floral aroma. Cracking the grain provides physical structure that keeps the koji bed aerated during fungal growth.
What is the yield of pressed liquid shoyu?
Typically, 1 kg of dry soybeans + 1 kg of roasted wheat yields approximately 2.5 to 3.0 Liters of unpasteurized raw soy sauce (Nama Shoyu) after pressing the fermented moromi cake through cloth filters.
Must finished soy sauce be pasteurized (Hi-ire)?
Yes, heating raw shoyu to 80°C (176°F) for 20 minutes denatures active enzymes to stabilize color, kills rogue yeast, and creates the dark caramel-red hue and signature cooked shoyu fragrance.