Fermentation and Reduction-Oxidation in Indigo Dyeing
Cozo Cazama is in his 14th year of cultivating indigo dye, following a method outlined in the 1960s by researcher Yoshimasa Takahara in Studies on the Reduction of Indigo in Industrial Fermentation Vat. Unlike many other natural dyeing methods, which involve boiling plant matter such as roots and leaves, indigo is fermented in the dyeing process.
Pigment is found in the leaves of the plant Persicaria tinctoria, a member of the knotweed family. However, once the leaves are harvested and dried, the pigment is becomes insoluble in water. To achieve a water-soluble pigment, the leaves must be fermented; the leaf compost, known as sukumo, is the raw material for indigo dye. This sukumo is then fermented again in a large vat or pot to make the dye solution. During this second fermentation, a dyer must pay close attention to the pH, temperature, and nutrient levels of the vat.
About Cozo Cazama
Owner of the indigo dyeing studio Airoza, located in Ashikaga City, Tochigi Prefecture. About twice a month, he conducts indigo dyeing workshops where participants rinse their finished textiles in a nearby river. Initially interested in the anti-microbial properties of indigo, Cazama has more recently come to think of indigo dyeing as an important part of the history of Japanese traditional crafts.