Sake Under Heat (2): Can New Rice Varieties Be the Savior of Sake?

As global climate change accelerates, heat damage to rice has become an increasingly serious issue for Japan’s sake industry. In the first part of SAKE Street’s special series, “Sake Under Heat,” we examined how rising temperatures are affecting Japan’s rice crops and summarized the measures that both farmers and breweries can take to mitigate the impact.

In response to ongoing temperature increases, research into heat-tolerant rice varieties—both for table rice and sake rice—has advanced rapidly in recent years. Yet, as discussed in the previous installment, some brewers view the introduction of new rice varieties as risky, often preferring to adjust their brewing techniques rather than switch to unfamiliar rice.

In this second part, we explore the potential of these heat-resistant sake rice varieties as a long-term adaptation strategy to climate change. We begin with insights from Numata, a sake rice farmer in Shimane, who also works as a licensed master brewer during the winter season and contributes regularly to SAKE Street. Speaking from the dual perspectives of both farmer and brewer, he shares the challenges visible from each side.

We then turn to Yamagata Prefecture, introducing a successful example of local collaboration in developing new rice varieties. Through their case, we consider what kinds of coordinated, nationwide efforts might be necessary to safeguard the future of sake production in a warming world.

Barriers to Introducing New Rice Varieties for Farmers

In addition to cultivating sake rice, Numata, a rice farmer in Shimane, also grows table rice and vegetables. During the winter, he works at a local sake brewery—this year marks his twelfth brewing season.

Japan’s rice production faces a multitude of challenges: an aging farming population, a lack of successors, and a continuing decline in rice demand. In 2024, soaring rice prices added another layer of difficulty, and the impact was felt in the sake rice sector as well.

“Both producers and consumers tend to judge prices simply by whether they’re higher or lower than last year, without a clear sense of what a fair price actually is,” he explains. “But when we think about whether production can continue sustainably, the issue goes beyond just the selling price.”

Considering that the national average farm size is about 1.8 hectares and the average annual income is around 60,000 yen, small-scale rice farmers can’t make a living unless they expand significantly. However, many sake rice varieties are unsuitable for large-scale mechanized cultivation, and because sake rice is planted based on the previous year’s demand, it’s not easy to increase production quickly.

“As farmers age, many retire because they can’t afford the high cost of new machinery,” he adds. “Sake rice production tends to be smaller in scale than table rice, so it’s even harder to invest in equipment.”

Given these realities, when a prefecture introduces new sake rice varieties, only a limited number of farmers are able to adapt. Recently, terms like jizake (local sake) and terroir have drawn attention to locally grown sake rice, but the Shimane farmer notes that not all regions have been able to respond effectively to this trend.

“For farmers, adopting a new variety carries risks—yields and quality may fluctuate. For breweries, there’s also uncertainty: they already have established product lines, and a new rice variety isn’t always easier to handle. In regions where sake rice cultivation is prioritized, local sake brewers’ associations often provide strong technical guidance, which helps maintain quality. But in other areas, individual farmers grow the rice on their own, resulting in large variations in quality.”

The Shimane farmer points out that introducing new varieties without addressing underlying issues—like aging, scale, and infrastructure—can make the situation even more complicated.

So, how can Japan’s sake industry respond to climate change, a nationwide challenge that affects every region?

In the next section, we’ll look at Yamagata Prefecture, a region that has succeeded in developing and cultivating sake rice through strong local collaboration.

Developing Sake Rice Easy to Use and Easy to Sell: Yamagata’s Collaborative Model

Two Prefecture-Wide Communities Supporting the Growth of Local Sake Rice

Yamagata Prefecture has become a national leader in cultivating and promoting locally grown sake rice. Through strong collaboration between farmers, breweries, distributors, and local government, the prefecture has successfully developed and branded original sake rice varieties such as Dewa Sansan, Dewa no Sato, and Yukimegami.

We spoke with Masumi Nakano, president of Dewazakura Sake Brewery and former chairman of the Yamagata Sake Brewers Association, about how two key communities within the prefecture have supported this achievement.

“In Yamagata, the Sake Brewers Association operates several specialized committees, one of which is the Raw Materials Rice Committee. In addition, we have two major organizations unique to our prefecture: the Yamagata Kenjo-kai and the Yamagata Prefecture Sake Rice Production Promotion Council,” explains Nakano.

The Kenjo-kai is a technical association composed mainly of toji from breweries across the prefecture. Its focus is on improving sake-making techniques through study sessions and active information exchange. Within the group, there are research teams dedicated to topics such as raw rice, commercial sake quality, and storage methods. Brewers collaborate on experiments and present their findings, and each year, breweries that win Gold Medals at the Japan Annual Sake Awards are invited to give lectures to share their insights.

Meanwhile, the Promotion Council was established specifically to advance sake rice production in Yamagata. It brings together representatives from breweries, farming cooperatives, distributors, and government agencies to promote research and development informed by on-the-ground perspectives from both brewers and farmers.

“The council hosts an annual ‘Excellent Sake Rice Contest,’ where outstanding farmers are recognized and their cultivation techniques are shared within the community,” Nakano continues. “To keep motivation high, the top performers receive incentives such as monetary awards and overseas training opportunities.”

Through these intertwined networks, Yamagata has built a model of collaboration in which all stakeholders—from rice producers to brewers—work together to develop sake rice that is not only technically suitable for brewing but also commercially viable.

Developing New Rice Varieties Through Long-Term Strategy

In reality, developing a new sake rice variety is something that no single brewery can accomplish alone. That’s why in Yamagata Prefecture, research and development are carried out on a prefecture-wide scale, with continuous dialogue between farmers, brewers, and government officials through the Kenjo-kai and the Promotion Council.

“Introducing a new variety requires more than simply responding to immediate, on-the-ground needs—it demands a long-term strategy for adoption and dissemination,” explains Nakano.

“One of the challenges with new sake rice varieties is that they are often slow to gain acceptance in the market. For brewers, it’s not just about the rice’s inherent quality—familiarity also matters. Take Yamadanishiki, for example: it has decades of history and data accumulated from all across Japan. In contrast, prefectural rice varieties have shorter histories and limited data, which makes it more difficult to fully understand their characteristics.”

For this reason, Nakano says, Yamagata has pursued a deliberate strategy in its breeding programs: rather than simply refining varieties used for premium sake (tokutei meisho-shu), the prefecture develops distinct new varieties that don’t directly compete with existing ones, each with unique traits and brewing potential.

“Dewa Sansan,” he explains, “was originally developed as an alternative to Miyama Nishiki, which was widely used in Yamagata at the time. Later, Dewa no Sato and Yukimegami were created as differentiated varieties that build upon and diversify from that foundation.”

Through such long-term, collaborative strategies, Yamagata has built a robust ecosystem where innovation, regional identity, and practical usability all evolve hand in hand.

Moreover, these variety development efforts also align with the needs of farmers. In Takahata, Yamagata Prefecture, rice farmer Yoshihiro Shiga has been cultivating sake rice for nearly 50 years. Until 2019, he also worked each winter as a kurabito (brewery worker) at Yonetsuru Sake Brewery, while conducting sake rice research through both the Kenjo-kai and the Promotion Council.

“From a farmer’s perspective, we want rice that’s easy to grow, stable in yield, and has large grains. Dewa no Sato was developed in response to that need. However, because Dewa no Sato has a very large shinpaku (starchy core), brewers found it difficult to polish. The improved version of that became Yukimegami. I think one of Yamagata’s greatest strengths is that the opinions of both brewers and producers are properly communicated to the research institutions,” says Shiga.

In recent years, in response to climate change, Yamagata Prefecture has been developing heat-tolerant rice varieties for both table rice and sake rice. Nakano explains that while Yamagata has long pursued a strategy of avoiding internal competition (cannibalization) by differentiating the purposes of its sake rice varieties, the same approach now guides their work on heat-tolerant strains:

“We’re not just developing rice that’s resistant to high temperatures,” says Nakano. “We’re also aiming to create varieties with distinct sake characteristics—different in style and flavor profile from the three existing ones (Dewa Sansan, Dewa no Sato, and Yukimegami).”

Shiga’s rice fields lie in a mid-mountain area near the border with Miyagi Prefecture. The higher elevation and good air circulation make his fields relatively resistant to heat damage, but he notes that other areas of the prefecture have not been so fortunate.

“To raise the overall level of rice cultivation across the prefecture, we conduct three joint field inspections each year with both farmers and brewers, organized by the Prefectural Agricultural Promotion Division,” Shiga explains. “It’s a valuable opportunity to exchange opinions, receive expert advice, and learn from each other’s methods—like how to manage water temperature more effectively. Visiting other farmers’ paddies and seeing their approaches firsthand is incredibly instructive.”

Keys to Developing and Promoting Heat-Tolerant Rice Varieties

Building on the success stories of regions like Yamagata—where collaboration among farmers, brewers, and government agencies has led to the creation of new sake rice varieties—how can similar efforts be scaled up and stabilized nationwide?

Why Is Nationwide Variety Development and Dissemination So Difficult?

Japan’s system for rice breeding has historically been decentralized, with each prefecture operating its own agricultural research center equipped with a breeding division. This structure evolved because Japan’s long, narrow geography spans diverse climates, making it logical for each region to develop rice varieties suited to its local conditions.

While this localized approach has enabled the development of varieties finely tuned to each region’s environment, it also has drawbacks. As Numata noted earlier, even excellent new varieties often fail to spread beyond their region of origin, leading to significant variation in quality and resources across the country.

This poses a particular challenge for heat-tolerant rice, since rising temperatures are a nationwide issue. Despite the shared goal, Japan’s prefecture-based system makes it difficult to coordinate strategy on a national level, often resulting in redundant investment and inefficiency as different regions independently pursue similar research.

Another obstacle lies in Japan’s branding system for rice, where rice is typically marketed as a combination of production area and variety. Because of this, adopting varieties developed in other prefectures can be seen as diminishing a region’s brand identity.

In practice, producers and agricultural cooperatives tend to favor varieties with strong market recognition. No matter how high the quality, rice developed elsewhere is often treated as an outsider and therefore excluded from local adoption.

This deeply rooted preference for regional exclusivity has become one of the major barriers to the shared development and diffusion of new rice varieties, even in the face of a rapidly changing climate.

Open Innovation in Agriculture: Learning from Global Models

Responding to climate change is not a challenge that can be tackled by a single region, brewery, or farmer—it requires collaboration across sectors and regions. For examples of large-scale, coordinated action, we can look to international agricultural initiatives.

In France, a nationwide breeding consortium called BREEDWHEAT was established through collaboration between the National Research Institute for Agriculture, Food and Environment (INRAE) and private seed companies, cooperatives, and research institutions. This major project brought together 26 organizations—including 13 public research institutions (such as INRAE research centers and universities) and 10 seed companies, cooperatives, and technical agencies—to develop new wheat varieties adapted to climate change. Running from 2011 to 2019, the initiative was backed by a budget of approximately 34 million euros (about 5.5 billion yen).

The European Union (EU) also provides a strong framework for agricultural innovation. Its Common Catalogue of Varieties lists registered crop and vegetable varieties from member states, allowing any variety approved in one member country to be commercialized across the entire EU. This system is made possible by sharing results from the DUS test (*)—an evaluation of Distinctness, Uniformity, and Stability—which ensures quality and enables the assessment of varieties across diverse climates and environments.

*DUS Test: A standardized examination used to determine whether a plant variety is clearly distinguishable from others (Distinctness), consistent in its traits (Uniformity), and maintains those traits over time (Stability).

In Japan, similar open-innovation models for variety development are gradually emerging. The Tohoku Agricultural Research Center, for instance, conducts monitoring tours where researchers from different prefectures share field trial results and directly observe one another’s studies to evaluate varietal adaptability across regions.

The Ministry of Agriculture, Forestry and Fisheries (MAFF) has also made climate change countermeasures a national priority. Under its FY2024 supplementary budget, it launched the “Emergency Initiative to Accelerate Development of Innovative Varieties,” a public grant program supporting the breeding of climate-resilient, high-yield, and machine-adaptable rice varieties.

In response, industry–government–academic partnerships are now forming across Japan to pursue these research projects—laying the groundwork for a more collaborative, resilient approach to agricultural innovation in the face of a warming climate.

Summary

In this article, we examined the challenges currently facing Japan’s rice cultivation through the lens of climate change, highlighting the need for collaboration across all sectors—from farmers and brewers to researchers and policymakers—to address them effectively. Beyond environmental issues, problems such as labor shortages, aging farmers, and rising production costs continue to strain the industry, making innovation essential on every front.

Sustainable rice cultivation is the key to the future of sake. As rice remains the core ingredient of sake, SAKE Street will continue to explore the complex issues surrounding rice production—and the innovations shaping its future—from multiple perspectives.

Sake Under Heat Sake Under Heat: How Climate Change Is Transforming Rice Cultivation and Brewing (1-2)

References

• Agricultural Management Statistical Survey: Production Costs of Agricultural Products (Individual Management Units), 2023 Edition, e-Stat, Government Statistics Portal of Japan.
• Takita, T., & Solis, R. O. “Rice Breeding at the Tohoku Agricultural Research Center and the Rice Variety Dissemination System in Japan.” Bulletin of the Tohoku Agricultural Research Center, No. 100.
• Yamagata Agrinet. “Why Don’t Farmers Just Grow Famous Varieties Like ‘Koshihikari’ for All Rice?”
• Fujii, Mizuho & Kamoshita, Akihiko. “The Current State and Challenges of Rice Seed Production in Japan After the Repeal of the Main Crops Seed Law.” Japanese Journal of Crop Science, Vol. 93, No. 2.
• Ministry of Agriculture, Forestry and Fisheries (MAFF). “Overview and Background of the Law to Repeal the Main Crops Seed Act.”
• Inrae Transfert. BREEDWHEAT Project.
• Bio-oriented Technology Research Advancement Institution (BRAIN) & MAFF Secretariat of the Council for Science and Technology, “Call for Proposals under the FY2024 Supplementary Budget: Emergency Initiative to Accelerate Development of Innovative Varieties (Policy-Oriented Open Call Type).”