Of course the very best comes from the island of Phú Quốc Vietnam. The island's 90 family owned factories produces 10 million liters of fish sauce per year. In fact, "Nuoc Mam Phu Quoc" (Phu Quoc fish sauce), is the most sought after in the world and is often imitated. In order to hold the Phu Quoc name it must come from the island and be made exclusively from the long-jawed anchovy.
Illicit production comes from neighbouring countries, which has led to Vietnam now enforcing an appellation d'origine controlee status. Vietnam Air embargoes all fish sauce off the island.