Shuhei & Miho Muto – Grape Republic (Nanyo, Yamagata)
Grape Republic was founded in 2017 by Shuhei and Miho Muto, together with a collective of friends and local farmers. Located in Nanyo, Yamagata, the winery sits in a region once known for table-grape cultivation but now revitalized by a new generation of natural winemakers.
The vineyards are managed organically with no synthetic chemicals, and the team grows varieties such as Delaware, Steuben, Niagara, and Muscat. Fermentations occur with native yeasts in concrete and amphora, and the wines are bottled unfiltered with no added sulfur.
Grape Republic’s vibrant, fruit-driven wines—ranging from pét-nats to extended-skin orange styles—embody a modern Japanese aesthetic of purity, spontaneity, and joy. Their striking labels and community-based production model have made them one of the most recognized natural wine brands in Japan.
Winemaking Philosophy: "Made from 100% Grapes"
Grape Republic adheres to a strict zero-zero natural winemaking philosophy, where the focus is on maximizing the expression of the local terroir—a concept they define as encompassing the climate, soil, people, and culture of Nanyo City.
Zero-Zero Approach: The wines are made of "100% Grapes," meaning absolutely nothing is added or subtracted. This includes:
No added sulfur dioxide (SO2) or other antioxidants.
No added sugar or acid adjustments.
Only natural/wild yeasts are used for fermentation.
Wines are typically unfined and unfiltered.
Organic Viticulture: The winery practices organic farming from the start, avoiding herbicides, pesticides, fertilizers, and insecticides.
Amphora Aging: A signature of their process is the use of large Spanish clay amphoras (terracotta jars) that are often buried in the winery floor. This ancient method allows for natural fermentation and aging, imparting unique texture and energy to the wine.
Preserving Acidity: The winery does not use Gibberellin treatment (a common practice in Japan to eliminate seeds in table grapes) because the acidity around the seeds is considered essential for natural winemaking.
Grapes and Wine Styles
Grape Republic specializes in a "freestyle" approach, often blending traditional Japanese hybrid varieties with small amounts of Vitis vinifera to produce wines that are vibrant, fresh, and energetic.