Koshu

The Story

Koshu arrived in Japan via the Silk Road over 1,000 years ago—making it Asia's oldest vinifera grape. This pink-skinned variety produces delicate whites that are revolutionizing Japanese wine.

Insider Story

Koshu's origins are debated. DNA analysis confirms it's Vitis vinifera with some Asian wild vine ancestry. The leading theory: it traveled from the Caucasus through Central Asia and China, arriving in Japan around 718 AD.

For centuries, Koshu was a table grape. Japanese winemaking began only in the 1870s, when the Meiji government sent two young men—Ryuken Tsuchiya and Masanari Takano—to France to study viticulture.

But Koshu wine remained obscure, sweet, and undistinguished until the 2000s. Then Grace Wine, Château Mercian, and others started making dry, European-style Koshu. The wines found international acclaim—Grace's Koshu won gold at Decanter World Wine Awards.

Yamanashi Prefecture, at the foot of Mount Fuji, is Koshu's heartland. The terroir—volcanic soils, high altitude, dramatic temperature shifts—produces Japan's finest examples. Production is tiny but quality is rising fast.

Technical Deep Dive

Koshu is unusual: a pink-skinned grape typically vinified as white wine. The skins contain anthocyanins, but winemakers avoid extraction to maintain clarity.

The grape produces light-bodied wines (10-12% ABV) with crisp acidity (6-8 g/L), subtle fruit (white peach, grapefruit), and delicate minerality.

Yamanashi's climate is challenging: humid summers bring disease pressure; winter cold limits vine growth. Pergola training ('tanazukuri') is traditional—it lifts grapes off wet ground but reduces concentration.

Modern producers are shifting to vertical shoot positioning and lower yields. The result: more concentrated, complex wines.

Sur lie aging adds texture and umami character—particularly suited to Japanese cuisine. Koshu's neutral character makes it a sommelier favorite for food pairing.

Industry Secrets

Koshu has struggled to establish global identity. Production is small (~500 hectares), exports limited. Most Koshu stays in Japan.

The 'Koshu of Japan' trademark now protects authentic Japanese Koshu. Beware Chinese knockoffs.

Grace Wine and Château Mercian are the quality leaders. Look for 'Gris de Gris' (skin-contact) styles and single-vineyard bottlings.

Koshu pairs uniquely with Japanese cuisine—the wine's delicate umami complements sashimi, sushi, and tempura like no Western variety can.

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• Krasnostop Zolotovsky
• Kuekfrankos
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