An Onomichi lager specialist brews an iyokan hard seltzer

What a beer-brewed “sour” means

The “sour” is a staple of Japanese izakaya: a distilled spirit such as shochu, topped up with soda water and fruit juice. Shimanami Brewery, a craft brewery in Onomichi, Hiroshima Prefecture, has made its version in a different way. It first ferments malt, just as for beer, to produce a clear, colourless brewed base. In Europe and North America this kind of alcoholic sparkling water is called a hard seltzer. Fruit juice is then added to finish it, so under Japanese liquor tax law the drink is classed as a malt-based happoshu (sparkling alcoholic beverage). For the new Shimanami Cho Iyokan Sour, the brewery used plenty of juice from iyokan grown in Ehime Prefecture on Shikoku, across the Seto Inland Sea. The iyokan is a thick-skinned, juicy variety of mikan, a type of mandarin native to Japan. According to the brewery, it worked repeatedly on the recipe so that, unlike a spirit-based sour, the drink would have the gentle fermentation aroma and natural sweetness that only a brewed base can give.

Iyokan sweetness, lemon acidity, and ice

The first sip brings the fresh aroma of iyokan and a clear sweetness. Lemon juice is added for acidity and to keep the finish light. At 3.0% ABV, it is deliberately low in alcohol and easy to drink. The brewery recommends comparing it with and without ice. With ice, the flavour turns tighter and sharper. Poured into a glass without ice, the acidity softens and mellows as the drink warms, and the aroma of the yeast comes forward. It comes in a 350 ml can, must be kept refrigerated, and has a shelf life of six months.

A small brewery led by a lager specialist

Owner-brewer Matsuoka Futo studied brewing science at Tokyo University of Agriculture and then served as head brewer at Yatsugatake Brewery in Yamanashi Prefecture. In 2020, three of his beers were named best in their categories at the World Beer Awards, an international competition held in the UK. That prompted him to go independent, and he began brewing in his home city of Hiroshima in 2023. Unusually for a small brewery, lager is its main focus. Its flagship Strike Pilsner, made with German and Canadian malt, won Japan’s top award in the Classic Pilsner category at the same awards in both 2024 and 2025. The first in the series, Shimanami Cho Lemon Sour, won a Good Design Award for fiscal 2025. According to the brewery, it is the first time a craft beer from a domestic microbrewery has received the award.

For now, sales centre on the brewery’s official website, and no distribution in Europe has been announced. Even so, there is plenty here for European readers. Japanese citrus is a new option in a hard seltzer market dominated by lemon and lime, and a serious lager brewery is turning its hand to low-alcohol fruit drinks. If you do get hold of a can, keep it chilled at all times, since it needs refrigeration, and try it both with and without ice. At specialist shops that stock Japanese craft beer, it is also worth pairing it with the same brewery’s pilsner to see the range of the brewers’ skills.