Bacalhau is not a Portuguese fish. It lives in the North Atlantic, thousands of kilometres from the Portuguese coast, and it has never been caught in national waters. It still became the backbone of the country's cooking, and there is a technical reason for that.
Why this fish
The answer is in the water the fish stops having.
Fresh cod is eighty per cent water. After wet salting it sits at around fifty-four per cent. Then it is dried, and what matters is not the moisture itself but the water activity, which falls to between 0.70 and 0.75. Below those values microbes do not develop.
Which means a salted, dried fish keeps for months with no cold, no tin and no vinegar. In a country that spent centuries crossing oceans and fasting by religious calendar, it solved both problems at once.
Portuguese law now sets a minimum of sixteen per cent salt in the muscle and a maximum moisture of forty-seven per cent. In soaking, which takes twenty-four to forty-eight hours, the fish takes back around twenty per cent of its original weight in water.
Newfoundland
There is no documentary trace of the first Portuguese campaigns on the Newfoundland banks. What is known is indirect and comes from cartography: Newfoundland appears on the Cantino planisphere of 1502.
The names associated with the area are the Corte-Real brothers, João Álvaro Fagundes and João Fernandes Lavrador. There are accounts of campaigns on the banks as early as the sixteenth century.
At the start of the twentieth century Portugal had barely a dozen ships at Newfoundland. By the 1950s the fleet had passed seventy. The campaigns ran from April to November.
The Estado Novo made cod a policy
On 5 June 1934, Decree-Law 23 968 created the Cod Trade Regulatory Commission. It controlled trade, consumption forecasting, imports, production methods, sanitary conditions and the modernisation of the fleet. The following year, on 23 November 1935, Decree-Law 26 106 created the guild of cod fishing shipowners.
The figures show what that did. Portugal was self-sufficient in fifteen per cent of the cod it consumed in 1934. By 1956 it was at eighty-eight per cent. Consumption almost tripled between 1934 and 1967, from fifty-one to one hundred and thirty-six thousand tonnes.
The protectionist policy ran from 1934 to 1967, and it was in that period that cod went from foodstuff to symbol of national identity.
Something the story usually hides: consumption was very uneven by region. The interior ate considerably less than the coast. Cod was never the daily dish of all Portuguese people.
The nickname fiel amigo, faithful friend, is far older than any of this. It already appears in chapbook literature of the late eighteenth century.
A thousand and one ways
People say there are a thousand and one ways to cook bacalhau, or three hundred and sixty-five, one for each day of the year. There is no count behind those numbers. They are idioms for uncountable.
What does exist are recipes with documented histories, and two are worth knowing.
Gomes de Sá
José Luís Gomes de Sá Júnior was born in Porto on 7 February 1851 and died in 1926. He was the son of a cod merchant and worked in a warehouse on Rua do Muro dos Bacalhoeiros, in the Ribeira.
The story that he sold the recipe to a cook called João, at the Lisbonense restaurant on Travessa dos Congregados, is presented as legend by the very institution that keeps the dish's memory. There is no primary document. The handwritten note that circulates with the recipe is not documented either.
In 2011, at the Seven Wonders of Gastronomy, Bacalhau à Gomes de Sá was a finalist. The fish category was won by grilled sardines.
Brás
The origin is not documented. The attribution to a tavern keeper called Brás, in Bairro Alto, rests on oral tradition.
The most datable anchor is literary: the writer José Gomes Ferreira, born in 1900, recalls eating the dish in the taverns of Bairro Alto as a teenager, and calls Brás its ingenious inventor.
What is certain is that the technique is older than the name. There are cod frigideiras in a book by Francisco Borges Henriques from 1715, and shredded cod with eggs and butter in Lucas Rigaud, around 1785.
Dried salted or soaked
There are three states and they should not be confused.
Green, or wet, salted cod is an intermediate product: the fish has spent fifteen days or more in salt and has not yet been dried. Dried salted cod is the finished product, after drying. Soaked cod is dried salted cod with the water back in, ready to cook.
Buying dried and soaking at home is more work and more control: forty-eight hours in the fridge with three or four changes of water gets you wherever you want. Frozen pre-soaked cod saves the time and removes the choice.
At the table
With shredded fried cod, a white with enough acidity to cut the fat. With cod roasted in the oven, with olive oil and potato, a light red served cool holds up better than a full-bodied one.
There is bacalhau on the table in both fado houses, in Chiado and in Alfama. Tables can be booked here.