Yunohama Onsen, one of the four hot spring resorts in Tsuruoka City, has long attracted travelers with its combination of sea, white beaches, and hot springs. On January 23, 2024, the "Yunohamawāru Project" inn training seminar was held at the inn "Kameya" in Yunohama, aiming to promote the circulation of local ingredients and create a sustainable community, nurturing its unique gastronomy tourism. Eighteen participants, including inn proprietors and head chefs, attended the seminar. It might be hard to imagine how gastronomy and sustainable communities intertwine, but regardless of the richness of tradition and culture, a community cannot thrive if it is depleted. Creating a cycle within the community that protects local agriculture, cultivates signature ingredients, and integrates them into business ventures ensures the continuity of regional agriculture and economy, laying the foundation for gastronomy tourism.


"Harnessing the Potential: Black soldier fly (Hermetia illucens) Research and Circular Agriculture Innovations"
The seminar was hosted by Yunohama 100 Year Co. and moderated by Mei Kirie of the company. It featured an introductory overview by Kimikazu Abe, who is also a director of the company, and began with an explanation of the project's foundation. This involves utilizing the larvae of a beetle called Black soldier fly to decompose food waste generated by inns and hotels, converting it into fertilizer to cultivate locally grown vegetables, thus creating a cycle. According to Abe, the idea for this project emerged when he was envisioning vegetables as the mainstay of Yunohama's unique gastronomy tourism, and coincidentally heard from Sho Okamoto of Sompo Japan about using the Black soldier fly to decompose food waste. Sustainable initiatives were already underway in Yunohama; the community had been collaborating with the Ministry of the Environment to utilize unused heat from hot springs for CO2 reduction. The collection and processing of waste from inns by a cooperative was also a natural progression. Abe emphasized the importance of not only delicious food but also the culture of valuing food that underpins gastronomy.

Next, Associate Professor Satoru Sato, who conducts research on Black soldier fly at the Faculty of Agriculture, Yamagata University, explained the process of decomposing food waste and converting it into fertilizer using these beetles. Black soldier fly are found throughout Japan and are also known as "toilet beetles." Despite their name, they do not transmit diseases and are being noticed worldwide for their high protein content. These larvae efficiently consume food waste, converting it into fertilizer (liquid fertilizer) without emitting CO2 or requiring energy consumption. Currently, Sato is processing 1 to 2 tons of food waste generated annually within Yamagata University using these beetles, with plans to handle the estimated 55 to 65 tons of food waste from Yunohama Onsen in the future. The fertilizer produced has been shown to have effects comparable to chemical fertilizers and is beneficial to the soil. Sato also highlighted the role of these beetles in providing protein, indicating the high potential of this approach, which surprised the participants.

Taking over the discussion, Kouichi Sato from Wats Wats Farm, located near Shonai Airport, explained how they cultivate a variety of vegetables such as melons, cherry tomatoes, spinach, and ginger on sandy fields. During winter, when colorful vegetables are scarce, they grow vibrant vegetables like yellow turnips and red carrots in greenhouses, which are also used in Yunohama's inns. Wats Wats Farm joined this project seamlessly due to their existing collaboration with Yamagata University in implementing circular agriculture. Furthermore, Sato expressed concerns about the rising selling prices of vegetables for farmers, with wholesale prices remaining stagnant, leading to the need to reduce production costs. Therefore, utilizing discarded food waste is expected to help control costs. However, since there is still no data on the optimal timing and quantity for effective use, trial and error will continue in the future.

"Sustainability Alone Doesn't Make Business Sense"
According to Abe from Yunohama 100-Year Project, no matter how environmentally friendly your initiatives are, if the food isn't delicious, the business won't thrive. To address this, Abe invited Naoto Suzuki, a longtime acquaintance from TOKYO KAIKAN in Marunouchi, along with Naoto Suzuki (Japanese cuisine advisor), to conduct a training session on pondering the "deliciousness" of Yunohama's flavors. Suzuki crafted two dishes using vegetables grown with fertilizer made by the Black soldier fly: "Tai Kabura-mushi with Japanese Sea Flavor," enhanced with the aroma of yuzu, and "Night and Day Daikon" paired with Beni-Zuwai Crab. These dishes were served to participants and the media present at the event, and everyone savored the deliciousness while receiving the lecture. Suzuki first noted that ingredients fall into three categories: those sought by "instinct," those sought by "reason," and those driven by "desire." Generally, profitable ingredients are those driven by "desire." Compared to beverages like sake, which fall into this category, vegetables sought by "reason" lack the persuasive power to appeal to customers. Therefore, detailed explanations were provided on preservation and cooking methods to enhance the goodness of vegetables. For example, Suzuki advised that daikon and turnips should have their leaves and roots trimmed, wrapped in newspaper, ideally hung at room temperature for storage, and buried vegetables such as root vegetables should have their skin peeled and exposed to sunlight once, emphasizing that proper preparation of fish before cooking leads to better flavor, and it's not just about pursuing freshness. It was an eye-opening lecture. Finally, Suzuki expressed a desire for dishes that would make people want to visit Yunohama when the season arrives and requested Sato from Wats Wats Farm to produce vegetables that can be eaten with their skin.

Yunohama has long been known for its "sea," "white beaches," and "hot springs." With this project adding "life" and "food" to the mix, it's likely that Yunohama's gastronomy tourism, which will continue for another hundred years, has been born.