Aizu Tenpo Genen Juwari Koji Miso (会津天宝 減塩十割こうじみそ)

The story behind it

Summers in the Aizu basin are hot, and winters shut the place in under deep snow. That severe swing between heat and cold is what shaped the flavor of Aizu miso.

Aizu Tenpo Jozo, founded in 1871, is a brewery in this castle town carrying that line forward. At its center sits a long-aged red, salty-forward rice miso, but its other pillar is a sweet koji miso with a high proportion of koji (the fermentation culture Aspergillus oryzae). This juwari koji miso is brewed with rice koji equal in weight to the soybeans.

The more koji, the further forward the sweetness of the rice comes. With the salt held back, the edges soften, and in miso soup it opens out gently. People used to salty-forward miso are often the most surprised by the sweet miso of Aizu.

Aizu has a food culture that treats soups as important, kozuyu being the best-known example. This is a miso in which the knowledge of preserved food, built up to get through hard winters, turned directly into flavor.