Shugyoku is a red vinegar (akazu) produced by Yokoi’s Vinegar in Tokyo for preparing traditional Edo-mae sushi. Its character reflects the style of vinegar used in sushi during the Edo period.

It is made from aged sake lees using traditional akazu production methods. As the lees mature, they gradually darken and develop more complex aromas, which carry through into the vinegar during fermentation. Shugyoku has an acidity of 5%.

It has a mild, rounded flavor, with the umami characteristic of red vinegar. It gives sushi rice a fuller flavor and a light brown hue. To prepare sushi rice, it is mixed with salt and sugar, then added to warm, cooked rice.