Comparison of the Three Legal Koji Types for Honkaku Shochu

(White · Black · Yellow – side-by-side, no marketing fluff)

Feature	White Koji (白麹 – Shiro Kōji)	Black Koji (黒麹 – Kuro Kōji)	Yellow Koji (黄麹 – Ki Kōji)
Scientific name	Aspergillus luchuensis mut. kawachii (formerly A. awamori var. kawachii)	Aspergillus luchuensis (Okinawa native strain)	Aspergillus oryzae (same species used for sake/miso)
Year “discovered” for shochu	1903–1910 (Kawachi Genichiro, Kagoshima)	Pre-1400s (Okinawa awamori)	1950s–1960s (borrowed from sake industry)
Main acid produced	Medium–high citric acid (0.6–1.2 %)	Very high citric acid (1.0–2.5 %)	Almost no citric acid (<0.1 %)
pH of final moromi	3.4–3.8	3.2–3.6	4.0–4.5
Contamination resistance	★★★★☆	★★★★★	★☆☆☆☆
Optimal temperature range	34–40 °C	32–38 °C	30–36 °C
Typical koji-making time	48–52 hours	46–50 hours	52–60 hours
Mycelium appearance	Pure snow-white, short “hair”	Grey → black spores very early	White → light yellow → green spores at finish
Aroma of finished koji	Sweet chestnut, pineapple, peach	Mushroom, forest floor, strong citric	Melon, steamed rice, sake-like
Enzyme profile	High glucoamylase, medium protease	Highest glucoamylase of all, high citric production	Highest protease, balanced amylase
Starch → sugar conversion speed	Very fast	Fastest	Moderate–fast
Flavour contribution to final shochu	Clean, fruity, peach–pineapple–banana esters	Funky, tropical, rum-like, earthy, long finish	Elegant, floral, ginjo-sake character, umami
Typical ABV off still	36–42 %	38–45 %	34–40 %
Oiliness / mouthfeel	Medium–light	Heavy, oily	Light–medium
Ageing potential	Good (3–10 years)	Excellent (10–25+ years, develops rum/whisky notes)	Very good (5–15 years, becomes sake-whisky hybrid)
Famous regions	Kagoshima, Miyazaki (imo shochu)	Okinawa (awamori), some Kagoshima/Miyazaki imo	Kuma (Kumamoto), Satsuma (rice shochu)
Famous flagship brands	Kuro Kirishima, Satsuma Shiranami, Tomi no Hozan	Zuisen, Kumesen, Zanpa (awamori)	Torikai, Hakutake Kuma Shochu, Yatsushika
% of total honkaku production (2025)	≈ 65 %	≈ 18 % (including all awamori)	≈ 12 %
Price range (720 ml, unaged)	¥1,200–2,800	¥1,500–4,000	¥2,000–6,000
Price range (aged 10+ years)	¥8,000–25,000	¥15,000–80,000+	¥12,000–50,000
Best matched main ingredient	Sweet potato (imo)	Rice (awamori) or sweet potato	Rice (kome shochu)
Heat tolerance in summer	Good	Excellent (originally bred for Okinawa heat)	Poor (easily contaminated in summer)
Current trend (2025)	Dominant, most new brands	Rising fast – bartenders love the funk	Small but growing – luxury “sake-whisky” niche

Real-World Distiller Opinions (2025)

Kagoshima sweet-potato masters:

“White koji is like a sports car – fast, clean, predictable. Black koji is a tractor – slow, powerful, unforgiving.”

Okinawa awamori masters:

“Black koji is our ancestor. It survives 40 °C summer and still makes beautiful spirit.”

Kuma rice-shochu masters:

“Yellow koji is calligraphy – every stroke has to be perfect, but the result is art.”

Which One Should You Try First?

Your taste preference	Start with
Clean, fruity, easy-drinking	White-koji imo shochu (Kuro Kirishima)
Rum/whisky lover, want funk	Black-koji awamori 8+ years (Kumesen Jo-goh)
Sake fan, want elegance	Yellow-koji Kuma rice shochu (Torikai Jo-karakuchi)
Want to taste all three at once	Buy a trio set – many distilleries now sell “koji comparison” packs

Bottom Line – 2025 Reality

They are not “better” or “worse” – they are completely different tools for completely different flavour destinations.

• White = the reliable daily driver (65 % of market for a reason)

• Black = the funky beast that survives anything and ages like rum

• Yellow = the delicate artist that makes liquid poetry but needs perfect conditions

All three are pure magic in skilled hands.

Drink one of each side-by-side and you’ll instantly understand why Japan has spent 500 years obsessing over a microscopic fungus.