nitrite/nitrate as tank brine above. The meat should be injected in about 20 places, deep into
the flesh. At larger scales of operation an electric injection pump with 5 - 10 needles can be
After curing, foods are cold- or warm-smoked for 6 - 24 hours to produce the required flavours
and colour. The texture remains mostly unchanged and products have a milder taste than hot-
smoked foods. These foods are preserved by refrigeration and are either cooked (e.g. bacon or
frankfurters) or eaten without cooking (e.g. ham, salmon).
Micro-scale smokers use a grill mounted above a smoky fire: meat or fish pieces are turned
regularly for 6 - 10 hours to ensure uniform heating and smoking. A traditional method for
smoking salted fish is to tie them in pairs and leave them hanging in air overnight to dry the
skins. They are then hung in a steel drum or a wooden barrel containing a hardwood fire and
sealed with a lid to create a hot, humid smoky fire without flames. They are smoked for an
hour and the heat and thick smoke produce a strong smoky taste and aroma.
Small-scale smoking equipment should allow the controlled development of flavour and colour
in foods, with low levels of environmental pollution caused by the smoke. Smoke can be either
generated within a kiln or smokehouse, or it can be produced by a separate smoke generator
(Figure 2). Smoke generators add to the cost but give better control over the temperature,
humidity and density of the smoke. A simple smoker can be constructed from an old
refrigerator by removing the compressor, cutting a vent in the top of the cabinet and fitting an
adjustable air vent in the bottom of one side. The smoke generator is a brick or metal cabinet
that contains the fire and has a vent to control the amount of air entering the cabinet. A pipe
is connected from the smoke generator to the vent in the side of the refrigerator.
Figure 2: Smoker with separate smoke generator.
(The Old Smokehouse at www.the-old-smokehouse.co.uk)
Smokehouses are larger than kilns and can be constructed from wood, concrete blocks, bricks
or galvanised iron. More sophisticated smokehouses have fans to evenly distribute smoke in
the smoking chamber. In small kilns, fillets of fish or meat and small products such as
shellfish or cheese are placed on wire mesh trays or hung from hooks, with space between the
pieces to allow smoke to penetrate all sides. In larger smokehouses, trolleys that have hanging
rails or mesh trays are wheeled into the smoking chamber. Whole fish are hung so that the
backs face the flow of smoke. Smoke from a smoke generator is passed into the base of a kiln
through a pipe, with or without the use of a fan.
Efficient smokers have low fuel consumption compared to the output; high capacity; and ease
of control without requiring constant attention. Examples include the ‘Altona’ design
developed by the Food and Agriculture Organization and the Chorkor smoker (Figure 3). The