Fish has always played a very important part in our diet being a precious commodity especially in areas without direct access to water. For those reasons the preservation played the main role and the taste was less important. Preservation was achieved by storing heavily salted fish in barrels where they were kept for months at the time. Caravans were able to move salted fish large distances and all the consumer had to do was to soak the 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.
|First you have to catch them||Then to clean them||And to smoke them|
Most of the bacteria in the fish is present in the slime that covers the body of the fish and in its digestive tract. There are two reasons that fish spoils faster than other meat:
- Its meat contains more water (bacteria need moisture)
- Beef - 60% water
- Veal, poultry - 66% water
- Fat fish - 70% water
- Lean fish - 80% water
- 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).
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. 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.
All fish may be smoked but the fatty ones absorb smoke better, stay moister 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 and washing
Unless a fish is of a very large size, it is not filleted but only gutted and cleaned on the outside. 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, filleted or hung in one piece. After cleaning, the fish has to be washed again. Previously frozen fish can be thawed, then brined and smoked.
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 or to use the brine tables. The fish is normally brined with a heavy brine for the following reasons:
- Its meat contains very little salt and a lot of water. These are the ideal conditions for the development of meat spoiling bacteria.
- Fish is home to an unusually high concentration of bacteria.
A 70-80% brine can be employed for all the common types of fish. By placing fish in a strong degrees brine we are performing an all out attack on the bacteria preventing them from growing. Salt penetrates the flesh of fish very rapidly and the brining times are relatively short, between 1 and 2 hours. Brines stronger than 80 degrees can deposit salt crystals on the surface of the fish skin creating unattractive white patches that can be difficult to remove. Fish brined in 90-100% brine will lose around 3% of its weight (water). We can get better and more uniform salt penetration if the brining times are longer but that will call for a 40 - 50 degree solution. In such a brine fish may be left overnight but will pick up about 2-3% of water that will have to be evaporated during smoking. Fish that will be smoked must be salted or brined first.
Brining provides the following advantages:
- Improves the flavor and looks of the fish.
- Improves texture-makes flesh much stronger which is important when fish is hung.
- Prevents growth of bacteria.
Salt penetrates fish easier in places that are open or cut than through the skin. A medium size herring should remain in 80 degrees brine for about 4 hours. Fillets need to be submerged in the same brine for only 20-30 minutes.
|Brine in degrees at 60° F||salt
|% salt by
A typical 80 degrees brine:
1 gallon water
2.25 lbs. salt (4 cups)
1 lb. brown sugar
2 Tbs. Cure #1
1/3 cup lemon juice
1 Tbs. garlic powder
1 Tbs. onion powder
1 Tbs. allspice powder
1 Tbs. white pepper
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. 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 the 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.
In order to eliminate nitrites (Cure #1) the salt concentration in the water should be high enough to inhibit the growth of C. botulinum, without making the product too salty to eat. A minimum concentration of 3% is considered to be effective for hot smoked fish. Also smoking and cooking temperatures should be kept above 180° F (82° C). People on a low salt diet who prefer low salt concentation in a product would be safer to include nitrites in the brine.
The brining time depends on the size of the fish and the salt concentration of the brine. Salt penetrates the flesh of the fish within minutes and brining times are much shorter than those for red meats. It is hard to derive time for fish fillets, fish with the skin on, and little fish or pieces of fish. The fish fillet will be oversalted if immersed for the same time in the same brine as a large fish. When brining many types of fish of different sizes 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.
|"Rule of thumb" brining times|
|Brine strength in degrees||Brining times|
|Brining times at 80 degrees|
|Fish fillets||Cold smoking||Hot smoking|
|½” fillets||½ hr||15 min|
|1” fillets||1 hr||½ hr|
|1 ½” fillets||2 hrs||1 hr|
|Whole fish||3-4 hours||1-2 hours|
The characteristic flavor of the fish is mainly due to salt and smoke but the texture of its flesh is greatly influenced by drying. A fish that was properly dried would acquire color much faster and would also develop a better taste. 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 to develop a type of shiny secondary skin known as “pellicle”. This gloss is due to the swelling of the protein caused by the salt in brine. Proteins dissolve in brine and create a sticky exudate on the surface. The longer the brined fish are permitted to hang, the better the gloss that develops. The best gloss develops with 70-80% brine. 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. Weaker brines or no salting fish at all leaves smoked fish with a rather dull appearance. The longer hanging time, the better results and a 1 hour period may be considered minimum. For a large fish 12 hours hanging time is not unusual.
The flesh of fish is delicate by nature and they have to be handled gently when hanging them on smokesticks 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. Place small fish pieces on smoking screens right from the begining of the drying process. Brush screens lightly with oil to prevent sticking of the fish.
- 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.
When hanging fillets it is advisable to leave the skin on otherwise the fillets may break apart.
Hanging small fish.
|Hanging large fish||Smoking over camp fire|
|Remove the sharp ends of the toothpick and spread the fish. This allows for better smoke and heat penetration.|
Cold smoking - fish is smoked below 80° F (26° C) from 1-5 days. If the temperature of the fish flesh exceeds 85° F (30° 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. Cold smoked fish is still considered raw meat as it was never submitted to high temperature. That is why it has to be heavily salted or brined at 16% salt (about 65 degrees brine) or higher to provide safety for the consumer.
The longer smoking period the more moisture is removed (30-50%) and the drier the product becomes with of course a longer shelf life. Its color also changes from gold to brown. This method of smoking can last up to a few weeks and the fish will have excellent keeping qualities. It should be noted that the final product will taste much saltier and its texture will be much harder. A cold smoked fish that is either fresh or freshly salted, must be cooked before consumption. 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 and longer brining times. Fish that were cold smoked hold 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 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.
Hot smoking is basically performed in three stages:
- A preliminary smoking/drying period at 86° F (30° C) during which the skin is hardened to prevent breakage. The air dampers are fully open for maximum air flow and moisture removal. This period lasts from 30-60 minutes.
- A heavy smoke is applied for about 30-45 minutes with the exit smoke damper left at ¼ open position. The temperature is gradually raised to 122° F (50° C).
- The temperature is raised to 176° F (80° C) and the fish is cooked to 145° F (63° C) internal temperature for a minimum of 30 minutes. Depending on the size of the fish this stage may last from 30–60 minutes. A light smoke may be maintained. When the temperature is raised to 176-194° F (80-90°C) we are smoking/cooking fish until its meat flakes out 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.
Smoking small fish.
Typical fish fillets smoking times are 4-5 hours depending on the size. When smoking is finished, the fish should be cooled rapidly to the ambient (50° F, 10° C) and then to lower temperatures (38° F, 3° C) to prevent the growth of microorganisms. This cooling process should be accomplished within 12 hours. Smoking fish is a lot of trial and error and record keeping. Notes should be made for future reference.
In the open fire smokehouse, the rear of the chamber is receiving most of the heat and re-arranging smoke sticks is a welcome idea. If the fish feels moist it is a sign that there is too much wet smoke inside and the draft must be open more. The back of the fish or the skin of the fillet should face the back of the smoker. That allows for the better judgment of the fish color and protects the flesh from higher temperatures that are normally found in the back of the smoker. When using a few levels of smokesticks insert the upper row first, then after 5-10 minutes the lower one, then the lowest one. If all three levels were placed in a smokehouse at the same time, the upper most row will get the least of the available heat during drying. On the other hand it will get the most moisture which will gather from the smokesticks below. Like in any other meat, the proportion of salt in the flesh increases during smoking and cooking because of drying.
Fish can be eaten immediately after smoking though most people will say that it tastes better when cold. 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. Freezing fresh fish in a home freezer is not the best idea as it is a relatively slow process. As a result large ice crystals form inside and affect the texture of the flesh making it mushy. Fish that are commercially frozen at much faster times don’t exhibit such symptoms.
Fish Flesh Color
Meat color is determined largely by the amount of myoglobin a particular animal carries. The 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. As a result they develop a darker color unlike the breast which is white due to little exercise. 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, tail, and the more active parts of the fish which are used for swimming. Most fish don’t have myoglobin at all. There are some antarctic cold water fish that have myoglobin but it is confined to the hearts only (flesh of the fish remains white but the heart is of a rosy color). The red color of some fish, such as salmon and trout, is due to astaxanthin, a naturally occurring pigment in the crustaceans they eat.
Most salmon we buy is farm raised and as it is fed a prepared commercial diet that even includes antibiotics, its meat is anything but pink. The only reason that farmed raised salmon flesh is pink is that canthaxanthin (colorant) is added to the food the fish eats. The pink color of smoked meat is due to the nitrite reaction with myoglobin. 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. 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 a 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:
“The reason nitrite is approved for use in those species is because someone submitted a petition for its use in those specific fish. Other species can be added through additional petitions.”
More information on fish sausages.