Shad marinated in vinegar for long enough to dissolved the many small bones, but not so long that it falls apart.
Dark soya sauce, koikuchi-shoyu, is the most commonly used in Japan for general cooking purposes and is served as a condiment at every meal. Alternatively, light-coloured soya sauce, usukuchi-shoyu, can be used to avoid colouring food. It is a little saltier than koikuchi-shoyu and lacks its complexity of aroma and flavour. Tamati-joyu is heavier, darker and richer than koikuchi-shoyu and is sometimes used as a dip.
