Cod's ability to be dried and salted made it the first mass-tradeable protein

Long before refrigeration, cod had a rare property that made it commercially transformative: its flesh is naturally low in fat, which means it can be dried and salted into a hard, lightweight, nearly indestructible product that keeps for years without spoiling. This turned a perishable fish into something closer to a durable good that could be shipped across oceans, stored through winters, and traded across enormous distances.

Kurlansky argues this preservability, more than taste or nutrition alone, explains cod's outsized historical importance — salt cod became a staple protein source for populations far from any coastline, feeding sailors on long voyages, provisioning colonial settlements, and even sustaining enslaved laborers on Caribbean plantations who were fed the cheapest cuts as a matter of plantation economics.

Because it traveled and lasted so well, cod effectively functioned as a form of edible currency in Atlantic trade networks for centuries, long before global food distribution existed in any modern sense.

Takeaway: a commodity's historical importance often rests less on its intrinsic quality than on a mundane logistical property, like how well it survives a long journey.