Natural drying is one of the oldest and most used methods for preserving food since ancient times
What is Natural drying?
The process of cod drying consists of some operations needed to extract a large part of the water from the fish tissues, at a level that salting has not yet achieved, thus increasing its conservation. To achieve the fundamental aspect of quick dehydration, the fish is salted in the first place.
Natural drying is, however, a process with enormous dependence on climatic conditions. If it is humid or rainy, evaporation does not occur, and if it gets rain, the product may be affected. On the other hand, if the weather is very hot, above 26/28º C and according to the conditions of humidity and salinity of the cod, changes in muscle mass and skin may occur, making the cod “burned” and unfit for consumption.
The process of drying
In the glorious times of national fishing, when the campaigns lasted from 5 to 6 months, ships arrived at ports with full holds. The catches were taken from the shops to the drying facilities on land. Here they dried the fish and prepared it for public consumption. The operation required a considerable amount of labour, usually women. The codfishes (already salted) were laid on a table, washed and brushed, and being exposed to sun and wind. These tables were simple drying racks made of wire or cord, to facilitate the fish drying through better air circulation.
However, given the conditions of the Portuguese climate, during the warmer seasons, the fish was laid on the racks very early and at 9 or 10 am it was collected and laid again at the end of the day, with cooler temperatures. When cod wasn’t outside drying, it was stacked. The procedure was repeated as many times as necessary to obtain the desired degree of cure. Fresh cod has about 80 to 83% of water and dried it will have about 45%, with a salt content up to 20%.
Artificial drying only appeared in some Portuguese companies in the 1950s, becoming a technique widely used only in the 1970s. The substitution of natural by artificial drying was a difficult and slow process and in 2017 the natural drying was prohibited by European regulations. In 2007, the Portuguese traditional codfish drying process, that existed since the XIV century and that gives the cod a good consistency, a long and intense flavour and a pleasant and pronounced aroma, was certificated as a Traditional Speciality Guaranteed (TGS) product by the European Commission.