One Christmas Eve when I was in elementary school, a heaping pile of buttered spaghetti sat on a platter on the buffet table in my grandmother’s warm, crowded kitchen. Since I was the kid who, to my parents’ annoyance as special orders upset the dinner flow in our large family, requested my pasta be served without sauce, I thought Nan was simply spoiling me again. But under this pile of plain-looking pasta, was a baccalà surprise. She’d prepared the dish to teach my generation of Italian immigrant offspring a lesson.

Baccalà is the Italian name for cod that has been salted and dried. “We think of fish as perishable and beautiful, a local, ephemeral food to be enjoyed fresh and simply cooked,” Gillian Riley writes in “The Oxford Companion to Italian Food.” Salted cod doesn’t necessarily have any of those attributes, Riley says. But cured fish does have a few sustainability points going for it. The process preserves regional, seasonal bounty. It has an extended shelf life, which reduces food waste. It requires less energy to transport because it’s light and doesn’t require refrigeration.

The production of salt cod dates back at least 500 years, to the time when Europeans discovered the Grand Banks fishing grounds off of Newfoundland. The abundant cod they caught there was dried in the sun, helped along by the salty wind while it hung on wooden scaffolding or was left lying on clean cliffs or rocks near the sea. Cod’s low fat content makes it well suited for techniques like this one. The process was developed to preserve fish in a pre-refrigeration era ahead of long journeys, ensuring that sailors had the nutrition they needed for months at sea. Salt was introduced to the natural process early in the 17th century, when increased production of salt in southern Europe led to lower prices, making it affordable to the maritime nations of northern Europe.

Salt cod formed a vital product of international commerce between the New World and the old one, securing its spot as a staple in Nordic, Mediterranean, West African, Caribbean and Brazilian cuisine. It was referred to as morue in France; bacalhau in Portugal and Brazil; bacalao in Spain, Puerto Rico, the Dominican Republic and Mexico; saltfiskur in Iceland; saltfisk in Norway; and klipvis in the Netherlands.

A hundred years later, along the coast of New England, cod was an abundant resource and domestic salt production was booming – it was established on Cape Cod by necessity during the Revolutionary War after the British Navy blockaded ports in the colonies, and intercepted supplies of salt, so that colonists could no longer import salt. By then, salt cod had become a mainstay of the American maritime economy, and it provided food for many, many poor Americans, says author, seafood advocate and chef Barton Seaver in “American Seafood: Heritage, Culture & Cookery from Sea to Shining Sea.”

The lesson my grandmother was teaching me on that Christmas Eve circa 1975 – at a time when salt cod had become foreign to most modern American children – was that my people had always eaten baccalà with plainly dressed pasta because it was a cheap pantry staple, even on Christmas Eve.

As an adult I’ve sampled brandade, salt cod cakes, croquettes, and even a sort of salt cod mayonnaise as baccalà has been rediscovered by Maine chefs in the past five years. I’ve developed a nuanced appreciation for the culinary potential of salt cod. Food scientist Harold McGee in “On Food and Cooking” says the best salted cod is the piscatory equivalent of salt-cured hams. “In both, salt buys time for transformation: it preserves [the fish] long and gently enough for enzymes of both fish and harmless salt-tolerant bacteria to break down flavorless proteins and fats into savory fragments, which then react further to create flavors of great complexity.”

Today, Norway is by far the largest producer of salt cod in the world. Canada is the largest producer close to home. Harbor Fish in Portland carries Canadian salt cod, both whole fish as well as smaller, prime cuts of cod that have been salted and boxed up.

Salt cod is also produced in Deer Isle, Maine – well, sort of. Stonington Seafood’s primary wholesale product is cold-smoked haddock. Owner Richard Penfield is British so finnan haddie is in his blood, so to speak. He also makes smaller batches of salt cod, available by mail order, and he preserves it in a manner he picked up while living in Shetland, a subarctic archipelago of Scotland that lies northeast of Great Britain. Shetland is closer to Iceland than it is to London and therefore has been heavily influenced by Icelandic maritime and culinary practices, Penfield said. He had a friend who was translating a 150-page document on Icelandic salt-curing practices and while he didn’t read the transcript, he did start studying the different methods for curing fish.

The one he settled on for his version of salt cod is a “green cure” method similar to the one used to cure herring in both Iceland and Shetland. Penfield sources his cod from Iceland where, unlike in New England today, the fish are numerous and yield large, thick fillets of consistent quality. He then salts the cod and puts it in a barrel. The salt draws the water out of the fish, and the two combine to form a “salt pickle” in which the fish sits for 15 to 20 days to develop its characteristic flavor.

The end product is still very salty, so must be soaked in water before it is ready to be used in any recipe. But the flesh is much more voluptuous than air-dried salt cod. When it’s cooked, it very closely matches the consistency of fresh cod, but has the complexity that McGee says it well worth the effort. This is not the cheap pantry food my grandmother taught me about – it costs about $20 per pound (for comparison, fresh cod loins are selling for $13.99 a pound at Harbor Fish Market in Portland). But I do think of her when I use it to make my version of her Spaghetti al Baccalà.

ABOUT THE WRITER

CHRISTINE BURNS RUDALEVIGE is a food writer, recipe developer and tester and cooking teacher in Brunswick, and the author of “Green Plate Special,” a cookbook from Islandport based on these columns. She can be contacted at cburns1227@gmail.com.