You are here: Lexicon › food preservation
Phenols, kerosols, formaldehyde or acetic acid let the protein of the food curdle and such preserve it. Since the smoke also changes the taste and smell of the food, it is nowadays used mainly as a flavouring method.
Smoking materials
Many different woods and materials can be used for smoking foods. In Europe most smoked foods used to be exposed to the smoke of beech or alder shavings or sawdust. In some countries such as Germany this is still the case. Others use oak more frequently nowadays. Juniper berries, fir or pine cones are sometimes added for flavour. More seldom spruce or pine shavings are used for smoking. In North America hickory, pecan, mesquite, maple and the wood of fruit trees are also used. Peat is used to smoke the barley malt for whisky and beer, ham and bacon is sometimes smoked over burning corn cobs. Every producer has its own special mixture of materials to obtain the perfect taste for his products.
Methods of smoking
Several methods of smoking are used. During cold smoking foods are smoked at temperatures of 16 to 26°C. It is mostly used for foods that are preserved for a longer time, for example ham, bacon, summer sausage, raw sausages, smoked salmon and herring (more specifically kipper). Warm smoking is done at temperatures of 23 to 40°C. It is also used for meat and sausages. During hot smoking the smoke has about 80 to 100°C. Since hot smoke does not penetrate the food completely it is used for products that are usually eaten fresh, for example herring (more specifically buckling), smoked eel or cooked sausage. Wet smoking includes a pan of water in the smokehouse or damp smoking wood to increase the humidity during smoking so the foods do not dry out.
Herring may either be cold smoked (called kipper if it is smoked split or bloater if it is smoked whole) or hot smoked (buckling). See also: smoked fish.
Liquid smoke
Alternatively foods are treated with liquid smoke flavours that imitate the smell and taste of smoking. This method is called wet smoking.
Liquid smoke is made from real smoke. The smoke is absorbed in liquids and sold in containers. Liquid smoke has several, mainly economic, advantages. It is cheaper, it does not produce smoke and it is standardized. Therefore the production of smoked goods of uniform quality, taste and looks is possible. Liquid smoke also contains less benzpyrene than real smoke. Since benzpyrene is considered carcinogen products smoked with real smoke should not be consumed on a regular basis.
In some countries such as Germany liquid smoke could only be used with special approval until recently. Now it is allowed in all countries of the European Union.