Woad was grown and picked in its first year. Leaves were chopped up, made into balls and left to dry until they hardened. The dried balls were broken into a powder, sprinkled with water and allowed to ferment, known as couching. When the couched woad dried. Hot water is poured onto the couched woad in the vat, adding potash or urine. This mixture would ferment for days before the dyebath is ready.