In sushi, grated shoga is used as a condiment,and a pickled version (gari) is eaten in between each sushi to cleanse the palate.
Shoga is very potent and can be very spicy. The rhizome becomes spicier as it grows deeper in the ground. However, the ones earthed near the surface have a sweet taste.
It is also used in sushi because it acts as a anti-bacterial agent, and increases blood flow in the stomach,when directly consumed. This aids in digestion, and helps keep the body warm after eating cold dishes such as sushi.
It naturally turns pink after a while, but most of them are artificially colored to cut production time. Some are used prematurely and retain a light yellow color.
Grated shoga is used in small amounts on some fish that have a deep flavor (such as Spanish mackerel) so that they can be brought out by the spice of the spicy ginger oils. Some are used to wash way strong smell such as fish oil (mackerel), and blood (bonito).
Grated Ginger (Oroshi Shoga) Pickled Ginger (Gari)
Gari, is thinly sliced ginger pickled in rice vinegar and sugar.