Smoking Fish

Smoked fish can be eaten immediately after smoking though most people will say that smoked fish tastes better when cold. Fish like other meats can be smoked by different smoking methods and the taste and shelf life will depend on smoke temperature and the length of smoking. Fish has always played a very important part in our diet and was a precious commodity especially in areas without direct access to the oceans or even lakes or rivers. For those reasons the preservation played the main role and the taste was less important. Preservation was achieved by heavy salting fish in barrels where they were kept well months at the time. Caravans were able to move salted fish large distances and all the consumer had to do was to soak fish in water to remove excess salt. Another technique relied on air drying to remove moisture from the meat thus eliminating favorable conditions for the growth of bacteria. Smoking fish was also effective as it prevented some bacteria from growing and removed moisture at the same time.

There are two reasons that fish spoils faster than other meat:

1. Its meat contains more water (bacteria need moisture)

    Beef - 60 % water
    Veal, poultry - 66 % water
    Lean fish - 70 % water
    Fat fish - 80 % water

2. Its meat contains very little salt (salt inhibits growth of bacteria). Both freshwater and saltwater fish have very low salt content in their meat (0.2 - 0.7 % of salt).

Salt acting almost like a magnet removes water from inside of the fish and at the same time migrates towards the inside of the meat where it inhibits the growth of bacteria. Heavy salting of the fish is practiced today only in most undeveloped nations and everywhere else we strive to give fish the best taste and flavor. And there is no doubt whatsoever that smoked fish tastes the best. Nowadays the preservation plays a secondary role as it is accomplished by refrigeration.

The flesh of fish is delicate by nature and they have to be handled gently when hanging them on smoking sticks or hooks. There are a few commonly used methods of securing fish for smoking:

    • Placing fillets or smaller pieces of fish on a screen, making sure they don’t touch each other
    • Inserting sharp pointed sticks through fish gills
    • Inserting „S” shaped hooks through the gills of the fish and hanging them on smoking sticks
    • Nailing fish directly to smoke sticks

Hanging large fish	Hanging small fish
Hanging fillets	Smoking over camp fire

When hanging fillets it is advisable to leave the skin on otherwise the fillets may break apart. All fish may be smoked but the fatty ones absorb smoke better, stay moistier during smoking and taste better.

Fat content of different fish:

    Lean fish < 2,5 %
    Medium fat fish 2,5 – 6,5 %
    Fat fish > 6,5 %

The same species of fish depending where they live (Europe, Atlantic or Pacific Ocean) may have a significantly different fat content in their flesh. Some of the lean fish: cod, flounder, grouper, haddock, hake, halibut, perch, pike, pollock, porgies, rockfish, snake eels, snapper, soles, tuna, whitting. Some of the fat fish: bluefish, carp, freshwater eels, herring, mackerel, mullet, sablefish, salmon, shad, trout, and whitefish.

The process of smoking fish consists of the following stages:

    • cleaning
    • brining
    • drying
    • smoking
    • storing

Cleaning Fish

Unless a fish is of a very large size it is not filleted but only cleaned on the outside, gutted making sure that the gills and all traces of blood are removed, especially the blood line along the back of the fish. Then depending on the size the fish is either cut across into 2” pieces, filetted or hung in one piece. After cleaning the fish has to be washed again. Previously frozen fish can be thawed in a refrigerator or under cold running water and brined and smoked.

Making Brine

This is a very crucial part of the process, unfortunately there is not an universal brine that can be used. The stronger the brine the shorter time of brining. A large fish and fat fish absorb salt slowly. Only fine non-iodized salt can be used as the iodized salt can impart a bitter flavor to the fish. The best solution is to use a brine tester also known as brineometer, areometer, salinometer or salometer. A fresh egg floating method can only roughly estimate the strength of the brine – the salt is added into water until an egg will just start floating with its tip above the surface.That corresponds to 40 – 45 degrees brine. It will of course float on the surface in all stronger brines ie. 60, 70, 80, 90 or 100 degrees. At 60 degrees the egg will start tipping over and at 70 degrees and above it will be lying on its side.

The most popular brine is the 80 degrees solution that contains a lot of salt in the water and the brining times are relatively short (1 – 2 hrs) as the salt migrates into the fish very fast. The salt will penetrate flesh of the fish better and more throughly if the brining times are longer but that will require 40 degrees solution. In such a brine the whole fish may be left overnight.
In such a brine fish may be left overnight but if the temperature of the brine will exceed 40º F we will face development of bacteria and the danger of food poisoning (Clostridium botulinum).

Note: Nitrites are not allowed in all species of fish used for smoking. The Food and Drug Administration currently allows nitrites to be used in salmon, sablefish, shad, chubs, and tuna.

Why out of millions of species of fish swimming in the ocean only five species can be cured with nitrite? What made those fish so special was the question that bothered me for a long time. Finally I had enough and the letter of inquiry was sent to the Food Safety and Inspection Service. And that was the answer to my intriguing question:

One gallon of brine is sufficient for 4 pounds of fish. Other ingredients like sugar and spices should be added to the solution after the correct brine strength has been established. Those spices will travel with salt inside of the meat and will create a particular flavor.

Fish pieces should be completely immersed in brine and covered with a weight plate. The temperature of the brine should not exceed 60° F (15.5° C) at the start of the brining. If the brining time exceeds 4 hours, the solution must be placed in a refrigerator (38° F) or ice should be added to the brine. Adding ice will change the strength of the brine and a better solution is to add re-usable blue ice packs. Keep in mind that brine loses its strength in time as the water leaves the fish and increases the volume of the original brine. At the same time salt penetrates the meat leaving behind a weaker brine. When brining times are long the solution’s strength should be periodically checked with a brine tester and readjusted accordingly.

Fish like any other meat is susceptible to food poisoning given right conditions for the development of C. Botulinum spores into toxins. Those conditions (lack of oxygen, humidity, temperatures 40° - 140° F) always exist when smoking meats. Furthermore many times fish will be packed by the Reduced Oxygen Packaging Method that can create favorable conditions for C.botulinum to become toxin even after fish was hot smoked and cooked. To eliminate the possibility of such a danger Cure # 1 is added the same way it is used when smoking meats or sausages.

Cure # 1 may be eliminated from the brine when hot smoking but the smoking temperatures must always be above 180° F (82° C).

more about Making Brines

more about Salt

Brining times

The brining time depends on the size of the fish and the salt concentration of the brine. It is hard to derive time for fish fillets, fish with the skin on, little fish or pieces of fish. It is logical to expect that the fish fillet will be oversalted if immersed for the same time in the same brine as a large fish. When brining a lot of different fish of different sizes it will be a good idea to use separate containers and classify fish according to its species and size. When using a single container, place small pieces on top so they can be removed earlier. The whole fish will require a longer brining time than a fillet.

Drying Fish

After brining the fish are carefully rinsed under cold running water to remove salt crystals and any traces of spices. The fish are then placed in a draughty area (fan works well) until they develop ”pellicle” which is a sort of secondary shiny skin. Pellicle helps in smoking and the final product has a nice glossy color. That normally requires 3 hrs time and is also of sufficient time to dry the fish for smoking. It is a good idea to place small fish pieces on smoking screens right from the begining of the drying process. Brush screens lightly with oil so the fish will not stick to them.

Smoking Fish

Cold smoking – fish is smoked below 80° F (26° C) from 1 – 5 days. Temperatures above 80° F will cook the fish. If the temperature of the fish flesh exceeds 84° F (29° C) for longer than a few minutes the protein will be coagulated and parts of the fish will be cooked. Such fish will not have the elasticity and texture of the properly cold smoked product.

After prolonged cold smoking the fish has lost enough moisture not to be cooked at all. A typical fish done that way is salmon or sturgeon. Cold smoking requires heavy brine. Fish that were cold smoked holds well together and can be very finely sliced which can not be done if the fish were hot smoked. Because of the time and costs involved this method is rarely used today.

Hot smoking – fish are smoked and cooked at the same time. Hot smoking (kippering) requires a lighter brine and a smokehouse temperature above 90° F (32° C). The fish are smoked/cooked from one to five hours. The fish can be smoked/baked in 30 minutes when the applied temperature is 300° – 350° F (150° – 180° C). Hot smoking is a commonly used method though the final product is tougher and more breakable than the fish that was smoked with cold smoke. The shelf life of the product is also shorter and the product must be kept under refrigeration.

Hot smoking is basically performed in two stages:

1. A preliminary smoking/drying period at 90° F (32° C) during which the skin is hardened to prevent breakage. The times depending on a size of the fish are 30 min – 120 min.
2. Then the temperature is gradually raised raised to 150° F (66° C) and smoking continues for remaining time from 60 min to 4 hrs. Nothing will happen if the temperature is raised to 176° – 194° F (80° - 90° C) and we are smoking/cooking fish until its meat separates easily when pressed with a knife or a fork. The cooking process will be shorter but the fish will taste drier. Fish is considered done when cooked to 145° F internal temperature for a minimum of 30 minutes.
 

Typical smoking times:

1/2” fillets 4 hrs 1” filets 6 hrs 1-1/2” fillets 8 hrs

When smoking is finished, the fish should be cooled rapidly to the ambient (50° F, 10° C) and then lower temperatures (38° F, 3° C) to prevent the growth of micro-organisms. This cooling process should be accomplished within 12 hours.

Oak, alder and beech will impart a heavier smoke flavor and fruit trees (cherry, apple, pear, etc.) will leave a sweeter flavor. Many people mix different woods together. In the North-Western USA alder was used to smoke salmon. Oak was always very popular in the United Kingdom.

Storing

Fish should be wrapped up in wax paper or foil and placed in a refrigerator where it can remain for up to 10 days. To hold it longer we have to freeze it.
 

Notes

Fish meat color. The pink color of the smoked meat is due to the nitrite reaction with myoglobin. Meat color is determined largely by the amount of myoglobin (protein) a particular animal carries. More myoglobin the darker the meat. To some extent, oxygen use can be related to the animal’s general level of activity: muscles that are exercised frequently such as the legs need more oxygen, and they develop a darker color (chickens). Fish float in water and need less muscle energy to support their skeletons. Most fish meat is white, with some red meat around the fins and tail, the more active parts of the fish as they are used for swimming. As most of the fish don’t have myoglobin the meat is not going to be pink and that explains why very few fish recipes include cure. In addition, nitrites are not allowed in all species of fish used for smoking. The Food and Drug Administration currently allows nitrites to be used in salmon, sablefish, shad, chubs, and tuna.

Smoking fish is a lot of trial and error and record keeping. Notes on brine strength and brining times should be made for future reference.

Sea water contains about 3.69 % of salt by weight which corresponds to 14 degrees brine.

The first step to sucessful fish smoking is to catch them says Adam:

Red fish	Snook