Through a cut in the throat, the gills and part of the gullet are removed from the herring, eliminating any bitter taste. The liver and pancreas are left in the fish during the salt-curing process because they release enzymes essential for flavor. The herrings are then placed in the brine for approximately 5 days, traditionally in oak casks. They require no further preparation after fillet and skin removal and can be eaten as a snack with finely sliced raw onion and pickles.