Cured fish facts for kids

Cured fish is fish that has been specially prepared to last longer before it's eaten. This is done using methods like fermenting, pickling, or smoking. These ways of preserving food can involve adding salt, special chemicals called nitrates or nitrites, or even sugar. Sometimes, the fish is also smoked or flavored, and it might even be cooked.

The very first way people preserved fish was by drying it out. Other methods, like smoking or salt-curing, have been used for thousands of years. The word "cure" comes from the Latin word curare, which means to take care of.

How Fish Curing Started

People started preserving meat by salting it in ancient deserts in Asia. Early salts had natural impurities like nitrates, which helped give cured meats their reddish color.

As far back as 3,000 BC, people in Mesopotamia (an ancient region in the Middle East) were preserving cooked meats and fish in sesame oil. Dried, salted meat and fish were a regular part of their diet.

Around 1,600 BC, people near the Dead Sea were using its salt. By 1,200 BC, the Phoenicians, who were great traders, were selling salted fish across the Eastern Mediterranean Sea.

By 900 BC, the Greeks were making salt in special "salt gardens," and they were good at dry salt curing and smoking meat. The Romans, around 200 BC, learned these methods from the Greeks. They also developed ways to "pickle" different kinds of meats in a salty liquid called brine. They noticed that salting made the meat turn red.

In the Middle Ages, using salt and saltpeter (potassium nitrate) to cure food was very common. People believed saltpeter caused the meat to turn red.

Salt Curing Fish

Salmon being prepared for curing

Salt (sodium chloride) is a main ingredient used to cure fish and other foods. When you add salt to fish, it pulls water out of the fish and also out of tiny living things (microorganisms) that can spoil food. This makes it hard for them to grow. To do this effectively, you need a lot of salt, almost 20% of the fish's weight.

It's best to use non-iodized salts, like those used for canning and pickling, or sea salt. Regular iodized table salt can make the fish look dark and taste bitter.

Sugar in Curing

Sometimes, sugar is added when curing fish, especially salmon. Sugar can come in many forms, like honey, corn syrup, or maple syrup. Adding sugar helps make the strong salty flavor less harsh. It also helps good bacteria, like Lactobacillus, grow by giving them food.

Nitrates and Nitrites

Nitrates and nitrites have been used for hundreds of years to help prevent a serious type of food poisoning called botulism in fish. They also help kill other bacteria, create a special flavor, and give fish a pink or red color.

The use of nitrates and nitrites in food is carefully controlled by rules and laws to make sure it's safe. For example, in the United States, the FDA (Food and Drug Administration) has rules about how much sodium nitrite can be used in certain fish products like smoked tuna, sablefish, salmon, and shad.

Smoking Fish

Equipment for curing fish used by the North Carolina Algonquins, 1585

Fish can also be preserved by smoking. This means drying the fish using smoke from burning wood or other plant materials. Smoking helps create a protective outer layer on the fish, making it harder for bacteria to get in. Smoking can be combined with other curing methods, like salting.

There are different ways to smoke fish:

• Hot smoking and smoke roasting actually cook the fish.
• Cold smoking does not cook the fish. If fish is cold smoked, it needs to be dried quickly to stop bacteria from growing before it's fully preserved. This is why thin slices of fish are often used for cold smoking.

Cured Fish Dishes Around the World

• Anchovies — Found in Europe and Southeast Asia, these small fish are preserved in brine, fermented, or dried.
• Bacalhau — Popular in Portugal and Spain, this is cod fish cured in salt and then dried. You need to soak it in water to re-hydrate and remove some of the salt before cooking.
• Dried cod — From Norway and Italy, this is dried, fermented cod. It also needs to be soaked before use.
• Bottarga — This is salted and cured fish roe (fish eggs).
• Ceviche — A dish where fish is "cooked" by being marinated in citrus juices, which cures it.
• Jeotgal — A Korean fermented seafood dish made with salt and spices.
• Po — Dried marine fish, especially Alaska pollock, popular in Korea.
• Gravlax — A Scandinavian dish of raw salmon cured with sugar, salt, and spices. It's similar to lox.
• Lox — From Europe, this is a cured salmon fillet.
• Matjes or Soused herring — Popular in the Netherlands and Eastern England.
• Pickled herring — Common in Europe, especially Scandinavia, Poland, North Germany, and the Baltic region.
• Pla ra — Used as a flavoring in Thai cuisine.
• Rollmops — A European dish of pickled herring fillets rolled around sliced onion and cucumber.
• Smoked salmon — Popular in Northern Europe, this is salmon that has been cured and then hot or cold smoked.
• Hákarl — From Iceland, this is Greenland or basking shark that has been cured through a special fermentation process and then hung to dry.
• Lutefisk — A Nordic dish made from dried whitefish. It's prepared by soaking it in a lye solution for several days, then soaking it in plain water to remove the lye, and finally cooking it.