A Guide to Smoking for Fish Preservation09 December 2014
For many fishermen and fish farmers, especially in Africa, smoking fish is one of the most important and efficient ways of preserving fish when refrigeration is not available, writes Lucy Towers, TheFishSite Editor.
The process of smoking allows fish to be edible for longer, easier to store and enhances flavour.
Over the years, various smoking techniques and styles have been used including traditional ovens or drums, altona smokers, banda smokers and the chorkor smoking kiln.
Many of the traditional oven designs proved unsuitable for smoking large volumes of fish and used unsustainable amounts of fuel - which in many areas has led to deforestation. There have also been documented health problems with smoke inhalation and burns with the use of these ovens.
This guide will therefore focus on the chorkor kiln as it is considered by many to be the most cost-efficient and effective method to smoke fish.
Benefits of Chorkor Smoking
The chorkor kiln was developed and first used in Ghana in the 1970's through an FAO project and provides many environmental, economic and taste benefits when large volumes of fish need to be smoked.
Compared with other smoking designs, the chorkor uses a small amount of fuel (50 per cent to a 1/3 of the wood required for other methods), smokes larger volumes of fish, takes less time to smoke, is cheaper to build and produces a better quality of fish with a longer shelf life.
The taste and texture of fish smoked in a chorkor is of a much higher quality than those smoked in a banda. Many reports show banda smoked fish as been black, brittle and with little taste, whereas in the chorkor, they are golden-brown in colour with a much stronger flavour. This increase in quality also means the fish fetch a better price at market.
With more control of air flow, the oven is also easier, healthier and safer to use.
The chorkor smoking kiln is comprised of a rectangular oven at the base and smoking trays which are stacked above the oven, forming a chimney.
The fire chamber(s), is usually rectangular or square in shape with walls of a 16cm thickness and is constructed of mud or bricks. The height of the chamber is usually 60cm and each chamber has a conical stokehole in the front for access.
The smoking trays should be the same shape and size as the oven chamber so that they can be stacked on top.
The 10-15 trays are usually made of wood-framed wire mesh. A sheet of plywood is then placed on top of the trays to act as a cover.
You can read a more detailed description of constructing chorkor smoking kilns in the FAO's Practical Guide to Improved Fish Smoking in West Africa.
The process of smoking cooks, dries and smokes the fish all in one.
Before being placed into smoking trays, large fish may need to be reduced in size by cutting into smaller pieces so that there is more surface area for moisture to be removed during the smoking process. If moisture is allowed to remain it may cause the fish to deteriorate quicker and be susceptible to insect infestations.
The fish are then placed into the smoking trays with the freshest and most moisture rich fish lowest down near the fire and the fish which are already partially dried, higher up the stack.
After the smoking process is complete, the fish will have a low moisture content and therefore can be kept or transported elsewhere for consumption. Fish can last from a week to a month, depending on the length of smoking.
Cost estimates for the construction of one chorkor are around €294 or $350. However, costs vary and most of the construction material needed can be sourced locally in many African villages.
You can find more information on fish handling and food safety by clicking here.