Tamagawa Shizenjikomi Yamahai Junmai Daiginjō Gyokuryū Muroka Namagenshu

"Gyokuryu" is a designation used for the highest-grade yamahai-brewed sake from Tamagawa, produced by Kinoshita Shuzō in Kumihama, Kyōtango (Kyōto).

Tamagawa Shizenjikomi Yamahai Junmai Daiginjō Gyokuryū Muroka Namagenshu (玉川 自然仕込 山廃純米大吟醸 玉龍 無濾過生原酒) is made with Yamadanishiki rice from Hyōgo, polished to 50%. It is brewed using the yamahai method (山廃仕込) and fermented with naturally occurring yeast in the brewery, without the addition of cultured yeast. The fermentation period extends to approximately 45 days, longer than typical for this category.

The result is a sake that combines the structure and acidity associated with yamahai brewing with the refinement of a daiginjo. It is produced in limited quantities, with both 720 ml and 1800 ml formats available. The sake shows a stable profile across a range of temperatures, from chilled to warmed. Its flavour and texture gradually change after opening as it is exposed to air.

Food pairings include grilled or cured fish such as mackerel, salt-grilled chicken, and richer dishes such as cream cheese with fermented seafood.

Kinoshita Shuzō, in Kōyama, Kyōtango, Kyōto Prefecture, was founded in 1842 by the fifth head of the Kinoshita family, Kinoshita Zenbei (木下善兵衛), who reportedly used the harvest from almost thirty hectares of rice fields and the copious spring water gushing from the mountain behind the brewery. The hereditary name Zenbei was passed down to the 6th and 7th generations. Then, the company was led by the 8th, 9th, and 10th generations (Sentaro, Zenichiro, and Juichi, respectively) before being handed over to Kinoshita Yoshito, the current president and the 11th in line.

The brand name Tamagawa can be translated as "Jewel River." The name is thought to refer to the Kawakamidani River, which flows by the brewery. The character 玉 (tama) means "jewel" and carries sacred connotations in Japan's native Shinto . 川 (kawa or gawa in compound words) means river.

Kinoshita Shuzō is one of the few Japanese breweries with a foreign tōji, Philip Harper. Born in the UK, he graduated from Oxford University. He taught English under the JET programme until he discovered sake. He worked at Umenoyado Sake Brewery for ten years before taking and passing the Nanbu Tōji Association's qualification test in 2001, earning him the title of 'Tōji'. He was the first foreigner to become a tōji (and the only one at the time). He then worked at Umenoyado Shuzō, Daimon Shuzō and other breweries before becoming tōji at Kinoshita Shuzō in 2008.

Kinoshita Yoshito gave him full responsibility for everything except following the locally favoured taste of regular sake and daiginjō. He immediately began producing kimoto sake, which does not use lactic acid during brewing, and yamahai, which uses only natural yeast from the brewery. In addition to new sake types like 'Icebreaker' and 'Time Machine', Tamagawa's legacy is reflected in the sake he produces.

Along with the new master brewer, the brewery's logo was redesigned by Sakane Katsusuke with an innovative design to symbolise the new Tamagawa. It is now widely known as the 'Marutama mark' (丸玉マーク).