Koshu Sanjaku (甲州三尺)
A 19th-century Yamanashi cross — one of Koshu's table-grape relatives, occasionally vinified but more often eaten fresh
What It Is
Koshu Sanjaku (甲州三尺) — literally "Koshu Three Shaku" (a shaku is a traditional Japanese unit of length, ~30 cm) — is a Yamanashi cross developed in the 19th century, named for the unusually long bunches the variety produces. The variety is genetically related to Koshu but distinct: thicker-skinned, less aromatic, and more vigorous.
Koshu Sanjaku appears in the parentage of several later Yamanashi crosses, most notably Kai Blanc (Koshu Sanjaku × Pinot Blanc, 1992).
Wine Style
When vinified, Koshu Sanjaku produces simple, neutral-to-slightly-grapey whites with low acid and moderate alcohol. The wines are generally not aged or developed for fine-wine ambition; the grape's commercial role has been as a table grape rather than a wine variety.
A small number of Yamanashi producers maintain old Koshu Sanjaku plantings and produce it as a curiosity or local-character bottling.
Why It Matters
Koshu Sanjaku is genealogically important rather than vinically central. Its role in Yamanashi viticulture is twofold: as one of Koshu's broader varietal family (alongside Koshu itself, Koshu Kyōho hybrids, and the various Yamanashi experiment-station crosses), and as a parent of Kai Blanc, one of Yamanashi's premium contemporary white grapes.
Details
- Origin: Yamanashi Prefecture, 19th century
- Type: Vitis vinifera-leaning hybrid, table grape
- Use: Primarily fresh consumption; occasional simple white wine
- Parent of: Kai Blanc (1992 Yamanashi Pref. Experiment Station)
- Plantings: Limited to historical Yamanashi vineyards