Smoking is a form of preservation, which reduces the moisture content of food slightly and gives it a certain amount of protection against bacteria, due to the chemical changes that take place within the flesh as a result of brining and the effect of smoked wood smoke on the salted flesh. Meats that can be smoked include bacon, hams, venison, beef, poultry and game.
The terms "hot" and "cooking" smoking can be a little confusing. But purists would say cold smoking, the method by which food is changed in both colour and flavour, is the only true smoking. Ideally, it is carried out in a temperature below 26ºC. Temperatures higher than that will cook the food, various components within the wood chips will vaporise and a hard skin will form on the food, resisting wood smoke penetration and resulting in inferior final product results. The usual method of smoking is to apply some heat to dry the meat and then to cold smoke it. This gives a dark-coloured product with very little smoke flavour, apart from the surface area near the skin.
Salt forms one half of the smoking process, the actual smoke being the other, so it is important that the salt is of the best quality available. When the term brining is used, the use of salt - either dry or in solution, with or without ingredients - is what is meant.
A salt solution, with sugar, sodium nitrate or sodium nitrite, spice or herbs and saltpetre is more often called a cure. The choice of method is dependent on:
? the raw material - the type of meat, its weight and whether the skin is removed or not. The total weight of meat is irrelevant. Time of brining is established by the weight of the individual pieces of meat
? the length of time it is required to be kept before eating.
The brining solution and time should be only strong enough and long enough to bring about the desired end-product result, which will then be eaten or frozen.
Sugar is added to brine because salt tends to harden flesh, while sugar tenderises and fixes colour. It also provides a medium for the bacteria necessary to break the sugar into organic acids, some of which give unpleasant flavours. The degree of saltiness in the brine can be a personal decision, but it must be strong enough to do the essential work of curing the food. By osmosis, brining commences the process of weight loss as water from the flesh is drawn out. While some professional smokers tend to think dry salting gives greater weight loss, others would argue that wet salting does. This will be counteracted by less weight loss during smoking. For the beginner, it is advisable to log the weight of the material after each step, so that a successful formula can be replicated again.
There are two schools of thought with regards to brining. Some butchers prefer strong brine and a short brining time; others prefer a weaker brine with a longer brining time. But it is worth noting that the stronger the brine used, the less time is required.
Once the brining process is complete, it is important to allow time for the meat to dry before you put it in the smoker. Some operators do not salt or cure meat before smoking and therefore the chemical changes, which give enhanced flavour and a characteristic golden coloured thin film or skin known as a "pellicle", do not form. The pellicle provides an ideal surface for the smoke flavour to adhere to and helps seal in remaining moisture. "If you can't cure it, you can't smoke it," says Barry Dean, smoking expert.
Smoking is ideally done by using a "smoker", which is a cooker specially designed for this purpose. A good smoker will provide even heat distribution, airflow and smoke. Companies like Bradley not only produce smokers but also bisquettes, which are basically hardwood chips bound together. Hardwood is used as, unlike softwoods, it will not give a bitter flavour to food nor release harmful substances.
The flavour of the smoke is determined by the type of wood being used. Alder and maple give a rich and distinct smoke flavour, commonly used with ham and bacon. Apple and cherry impart a sweeter, milder smoke flavour that is commonly used with poultry and wild game meat. The stronger and very distinct flavours of mesquite and hickory are commonly used for smoking beef and pork products such as pork shoulders and beef brisket.
Having been cold smoked, some foods are then hot smoked to enable them to be eaten without further preparation. The final process is normally short, in order to kill bacteria or to make the flesh tender enough to eat. If no cold-smoking time has been given to food, it would be more accurate to describe the food as barbecued.
Since smoking food is all about enhancing flavour it is important that this side of the process is given priority. Cold-smoked products can be offered to consumers to be cooked by normal methods, without a loss of final flavour. But remember that it is vital you give them instructions for cooking, so that no risk is involved.
Top Tips for poultry and game birds
? Remember to remove the kidney, which lies on either side of the vent, and make sure the bile ducts are removed as this prevents the acid in those organs being given out when they come into contact with the salt, giving an unpleasant flavour.
? When curing poultry or game birds, add a little sugar to stop hardening of the texture.
? Remember that the addition of red wine, cider, herbs and spices, or your individual selection of flavouring, will produce an individually designed product to make your mark. Your choice of curing agent - there are various proprietary brands you can use should you choose - will also be added to the brine at this stage.
? Try a small amount of the flesh and, if the product is too salty, put it in fresh cold water and keep changing the water until the extra salt is removed. Do not soak in the water, but keep changing it so that the salt is extracted.
? Oil the surfaces and if they become dry during smoking, brush on a little more oil. Remember that the colour and flavour will deepen.