To ensure more firmness to the flesh of a fish before cooking, an ancestral technique consists of salting and desalting the fish. Find out on Mise-en-Place how this is used in contemporary cooking.
Salting fish before cooking: the science behind the technique
Salting fish fillet preliminary to its cooking can be done in two ways: dry salt and brine. It is used to limit exudate – a result of coagulation of sarcoplasmic albumin – which occurs when the temperature is increased during cooking.
This salting, limited in time, aims to block the albumin inside the cell. To do this, salt – whether applied dry or in an aqueous solution – will increase the osmotic pressure inside the muscle cells of fish. From a microscopic point of view, the water cells are massaged against the cell walls, which they put under tension. As a result, these molecules block myoalbumin inside the sarcoplasm of the cell.
These two effects – pressurization of the cell and retention of myoalbumin – allow to modify the appearance of the fish as well as the perception of its color: the cod becomes whiter and the coloration of the salmon more intense.
In practice the two salting methods are used and not only when cooking fish. Salting is a technique that is also used for enhancing the flavours of sashimi.
– dry salting with coarse sea salt.
The fish fillet, placed on a layer of coarse salt, is covered over all its surface by the same salt. The salting time is between 12 and 15 minutes for lean fish such as cod or pollack, and between 15 and 18 minutes for oily fish such as salmon. After salting, the fillets are quickly rinsed under water to remove salt adhering to the flesh. They are dried and left to rest for at least one hour in a cold room. This rest allows the salt to penetrate the flesh, which in turn regulates the water activity in the surface of the fillets or portions.
RECIPE: Click here for the salting striped bass fillet recipe.
– Salting by immersion in brine
The duration of salting in brine varies from 10 to 20 mins depending on the type of fish and its thicknes. The concentration of brine also varies: 10% salt in water for oily fish, and 5% salt in water for lean fish. The brine must be maintained between 15 and 20°C, to facilitate the dissolution of salt in water and penetration in the flesh.
RECIPE: Click here for the precise temperature cooking of pre-salted fillet of sea bass recipe.
– Salting for raw fish sashimi
Salting and desalting also applies to the preparation of raw fish for sashimi. A technique used and perfected by Tomoyasu Kamo from the restaurant Kamo in Brussels.
RECIPE: Click here for the salting raw fish sashimi recipe.