Development of a New Wine Grape: Muscat Shiragai
At a press event hosted by OUS University, Professor Hoshino shared his ambitious vision for developing a new wine grape that combines wild genetic traits. If this grape is widely cultivated and its wine contributes to boosting tourism and regional development, it would be the optimal outcome.
Inspiration from a Rare Wild Grape
Professor Hoshino, an expert in plant taxonomy, established the Institute for Viticulture and Enology Studies at OUS University in April 2017. During his collaboration with the Funao Winery in Kurashiki City, he became interested in the Shiraga grape, a rare and endangered wild variety found only in specific parts of Okayama Prefecture. This discovery inspired him to develop a locally original wine grape by combining Shiraga with Muscat of Alexandria.
To implement this idea, OUS University signed a comprehensive partnership agreement in February 2018 with Kurashiki City and Funao Winery. This collaboration became part of a national initiative focusing on regional revitalization and “marketing local resources,” positioning the project as a scientific and cultural effort.
Development of “Muscat Shiragai”
By the fiscal year 2022, the team produced wine varieties from several experimental breeding lines. Each was tested to determine sugar levels, acidity, pH, and overall taste. After years of refinement, the most promising strain was selected, and “Muscat Shiragai” was officially announced as a new variety in 2024.
A joint registration application was submitted by the Kaki Educational Institution and Kurashiki City in December 2024, with full registration and approval expected to be completed within the next four to five years.
Warm Reception at the Press Conference
The press conference included key representatives such as Kurashiki Deputy Mayor Kenji Komatsu, Funao Winery CEO Kenichiro Miyake, and OUS University President Hiroyuki Hirano. Attendees tasted Muscat Shiragai grapes and the wine made from them. The grapes were described as “sweet and very delicious,” while the wine impressed tasters with its light Muscat aroma and smooth drinking quality.
Deputy Mayor Komatsu expressed optimism, saying, “We eagerly anticipate offering a wine filled with the unique charm that can only be produced in Kurashiki. We also expect further research results to enhance Muscat Shiragai into a more refined grape.”
CEO Miyake added, “With Muscat Shiragai as a branded grape, we hope to create a high-value red wine known as originating from Kurashiki. We look forward to the day we can bring this to market.”
Cultivation and Future Prospects
Currently, 20 vines of Muscat Shiragai are being cultivated at Funao Winery and the OUS University vineyards, producing 41.6 kilograms of grapes in 2024. Additionally, 300 grafted vines were planted by the end of the fiscal year 2023. The goal is to harvest more than 500 kilograms by 2028-2029. The research team is also improving vineyard management techniques, such as leaf removal, fertilization, and irrigation, to enhance grape quality.
Historical Legacy of the Shiraga Grape
The Shiraga grape was first identified as a new species in 1918 by renowned botanist Tomitaro Makino. Its Japanese name honors botanist Jekishi Shiraga from Niimi City, who discovered the plant. This wild grape is known for its naturally high sugar content, low acidity, resistance to fruit cracking, and tolerance to diseases like black rot and ripe rot.
Conclusion
The initiative to develop the “Muscat Shiragai” grape holds significant potential for promoting regional development and tourism in Kurashiki. By integrating the wild genetic traits of the Shiraga grape with Muscat of Alexandria, the project aims to create a distinctive wine grape that will become a local brand. The collaboration between industry, academia, and government contributes to building innovative local communities and promises to deliver research outcomes that benefit society and address regional and social issues. With positive future prospects, “Muscat Shiragai” seems poised to play a major role in the wine industry and local economic revitalization.