All you need to know about salting fish
“Klippfisk”, or clipfish, are fish that are salted and dried. Klippfisk contains 20 % salt and thus needs to be soaked or steeped in water before you can eat it – the salt levels need to be down to 2-3% for the fish to be edible. Saltfish are fish that are salted, but not dried.
Why do we salt fish?
Before the refrigerator and freezer were invented, there were many ways to preserve fresh food to be able to keep it for longer. Salting and drying are some of the oldest methods for preserving fish and meat. When the fish is put in salt, water is extracted from the fish and the salt enters the fish meat. After one month’s salt maturing, the saltfish has a water content of approximately 55% – and that water is saturated with salt where few microorganisms can survive and the activities of several enzymes are reduced, meaning the fish is preserved. The fish matures during storage and acquires the characteristic saltfish flavour.
Saltfish cannot be stored under hot and humid conditions. To make saltfish withstand storage better, it needs to be dried until the water content is less than 48% – at which point it becomes klippfisk.
Saltfish and klippfisk contain a lot of salt in order for it to be stored for long periods of time. Before we can eat it, we need to remove most of the added salt by soaking the fish in water. This may sound simple enough, but the way we soak the fish does in fact have a great impact on the taste – we need to achieve just the right salt level and preserve that delicious fragrance and flavour.
What happens in the fish when it is salted?
The salt has a preserving effect as it extracts water from the fish muscle and transports salt into it. The salt lowers the water activity inside the muscle, making the remaining water less accessible for microorganisms, which inactivates or inhibits microbial growth. In addition, the salt helps change the structure of proteins and deactivates certain enzymes.
Salting meat and fish therefore does not only have an impact on the saltiness, but also alters other components in the meat. As a result, dried and salted cod (klippfisk) often has a richer taste and smell than fresh, unsalted fish.
How do you salt fish?
Prior to salting, the fish is either filleted or split into two parts with the front part (approximately 2/3) of the spine is removed. After splitting, any residual blood and black membranes in the belly are removed. The fish is then spread open and placed skin down before it is salted.
Traditionally we have three ways of salting fish: brine salting, pickle salting and dry salting.
For brining or brine salting, one would first make brine with the desired salt concentration by mixing salt and water. You would then lower the fish into the brine, and keep it there until the fish reaches the right salt content. Salt brine can also be injected into the fish muscle.
Pickle salting is done by layering the fish with copious amounts of salt between each layer in a sealed container. During storage, the fish releases water, creating a salty brine. This process usually takes from 2 to up to 14 days. Pickle salting is usually used in combination with dry salting, either by placing the fish in a new batch of salt or by draining the brine from the container. All the brine which is formed as a result, is drained away from the fish until the desired salt and water levels are reached.
In dry salting the non-skin side of the fish is covered with salt. The fish are stacked in layers with copious amounts of salt between each layer, in a container which allows for the brine that is formed to be drained out of the container during the salting process, and left until it is fully seasoned.
How to make the best saltfish
In order to ensure optimum salt maturation of fish, it is important to control the temperature just right. In this video you can see how it’s done.
Film: How to make good salted fish
In order for salt maturation of fish to take place in an optimal way, it is important to control the temperature correctly.
In this movie you see how it should be done.
After 4–6 weeks of salt maturation, the fish muscle contains around 17–18% salt and around 57–58% water. Before the fish is dried to become klippfisk, it is important that it is fully salted and matured under controlled conditions to promote the fish’s natural maturation process and inhibit microbial growth during storage. After it has been dried to become klippfisk, the salt content is around 19–20%, whereas the water content has been reduced to between 50–53%. Variations in the methods used for salting and drying the fish can give variations in the salt and water content of the finished klippfisk.
A finished klippfisk will keep for at least 2 years if stored in a dark and cool place (2–4°C).
Shelf life and food safety