A Copenhagen-trained chef creates this shop’s modern fare. One example is the fermented dishes, inspired by the unique character of northern Europe. The restaurant takes special care with its acids, from which its name derives. It uses the acid from the fermentation process to add sourness and umami to its cuisine, such as in its pickled vegetables and mushrooms pickled in brine and fermented rice bran. Japan, after all, is another of the world’s foremost fermenting countries. Fermented items created in Azabu Juban make this restaurant a treat.