Junmai daiginjo ( 720 ml)

Tengumai's yamahai method — a labor-intensive natural fermentation using ambient microbes — dates to pre-industrial sake brewing. This Kanazawa expression leverages the region's famously soft water, drawn from the Kuzuryu River basin, which historically shaped the brewery's house character.

The brewery sits in Ishikawa Prefecture's Kanazawa district, where winter snow and moderate continental climate create extended fermentation windows. The junmai daiginjo specification indicates rice polished to 50% or less, concentrating amino acids and esters while removing starch-heavy outer layers.

Yamahai fermentation — initiated without temperature control or pure yeast cultures — produces a slower, more oxidative pathway than modern sokujo methods. This generates higher acidity and umami-forward compounds. The process typically spans 30–40 days, building complexity through wild Lactobacillus and natural enzyme activity. Tengumai's soft water minimizes mineral interference, allowing the fermentation's own acids to dominate the flavor profile.

Special feature: Yamahai junmai daiginjo is a rare intersection — most yamahai expressions use lower polish ratios (honjozo or junmai). The daiginjo polish here creates tension between the method's rustic, acidic backbone and the delicate ester profile expected from high-polish rice.

Drinking window: 2–5 years from release. Serve chilled (45–50°F) to accent acidity and mineral structure.