Koshu Tanino (甲州谷野)

The Variety

Koshu Tanino (甲州谷野) is a Japanese-bred grape variety created in the early 20th century — sources vary on the exact date, but most place it in the 1920s or 1930s — through a cross of Yamabudou (the indigenous Japanese wild vine, Vitis coignetiae) and Koshu (the Yamanashi vinifera). The breeding was performed at Yamanashi-area research stations, before the postwar formalization of breeding programs.

The cross logic was straightforward: combine Yamabudou’s extreme cold tolerance, disease resistance, and high acid with Koshu’s vinifera character and table-quality fruit. The result was intended for dual-purpose use — table grapes and modest wine production.

Style

Koshu Tanino wines are distinctive: deeply pigmented (more than Koshu, less than pure Yamabudou), with high acid, modest sugar, and a wild-fruit aromatic register that recalls Yamabudou rather than vinifera. The wines are usually vinified with skin contact to capture color and complexity.

The variety does not produce wines that easily compete with international standards in the conventional sense — they are more like aromatic wild-fruit reds than like Pinot Noir or Merlot — but they have a small dedicated following among natural-wine drinkers interested in indigenous-leaning Japanese material.

Where It’s Grown

Plantings are very small (well under 50 hectares nationwide) and concentrated in Yamanashi and adjacent Nagano. A handful of producers — Lumière, several Katsunuma small-domain operations, and a few Nagano natural-leaning producers — grow it in small parcels.

Why It Matters

Koshu Tanino is one of the lesser-known indigenous-leaning Japanese grape crosses, alongside Yamasochi and other early-20th-century projects that did not gain commercial traction at scale. Its persistence — never fashionable, never disappearing — represents the long-tail of Japanese viticultural identity that the natural-wine generation is now revisiting.

Details

• Color: Black (pink-skinned)
• Parents: Yamabudou (V. coignetiae) × Koshu
• Bred: Yamanashi area, early 20th century
• Plantings: Small (<50 ha)
• Major regions: Yamanashi, parts of Nagano