About the Author:
Executive Head Chef at the Glenview Hotel, Co Wicklow, MSc in Food Product Development and Molecular Gastronomy, BSc In Chemistry and Physics, Degree in Hotel Management, Multi Awards winner in various national and International Competition, Qualified WACS Judge, Active Member of Panel of Chefs of Ireland.
The Art of Smoking Food
History of Smoking
Throughout the ages, Humans did anything and everything to survive. Some went along with nature and learned how to grow while others started breeding and killing animals for survival. It wasn’t long after when Humans realised that much of the fresh meat was wasted having gone bad due to lack of any preservation technique.
It was the presence of increased brain size in Humans which quickly made them realise that cooked food was much easier to chew and digest. Although there is no exact evidence as to when fire was discovered or when it was domestically adapted by humans for purpose of cooking, it wasn’t long after that humans realised that when food was left near the fire, it acquired a likeable smokey flavour and much to their surprise it lasted longer.
As Humans learned to make shelters after moving out of wet caves, it was probably in autumn when they started hunting and killing animals as a long icy winter would impede growing or to fishing. It was then when meats where sliced and smoked to enable them to be preserved for long winter ahead.
Smoking for preservation
In Medieval Europe, when an animal was slaughtered, much of a meat was kept for smoking. This practice was common when a pig was slaughtered, which may be due to the high fat content in the animal and the resultant ability to sustain the heavy smoke flavour. Pigs were slaughtered more than cows and sheep as they were only raised to be eaten while cows provided milk and sheep provided milk and wool. Milk was then processed into cream, butter and cheese which furthered inventions by humans in order to preserve milk. The layered fat content in Pig’s meat allowed it to absorb smoke more than any other meat and kept the product moist for days after the smoking process.
Preservation of food not only made the food to last long at home but also made it easier to be transported by sailors, soldiers, traders or pilgrims. Smoking of fish meant that they could be enjoyed in long winter months as well, when fishing would be impossible because of heavy snow and ice.
Figure 3: Medieval Smokehouse
Technique of Smoking
As the other methods of food preservation like Canning, Freezing and pickling were invented, keeping food for longer wasn’t the priority when smoking was considered, it was all about the taste, texture and flavours.
Smoking of meat/fish is often preceded by a process of extracting moisture known as ‘Curing’.
Curing which is often referred as salting was historically one of the most prevalent methods of preservation. During the process of curing, salt is used to coat the meat in order to extract the moisture.
Ham Ready to Pack in Salt
Throughout the Curing process, moisture is extracted from the meat which is drained off until its dry and moisture free. Due to this process meat can be stored for a longer time but needed to be soaked and rinsed in fresh water to be able to extract the salt. Process of curing can take hours, days or months depending upon the size of the meat.
In modern times, a cure can be made of salt or sugar or a combination of both and a mixture of spices, herbs and syrups. A cure must be a blend of the right amount of ingredients to be able to achieve the desired result.
Another important aspect of curing is that it should be performed on a fresh produce, like a meat or fish in order to achieve a high-quality product. This can also be understood if the meat/fish is stale and has bacterial growth on the surface and is subjected to curing process, it does not preserve the product. The salt utilised to perform curing must be a food grade without any additives as it could result in less anticipated product.
In order to achieve a fairly standard product all around, all products of same nature should be of similar sizes. Penetration of salt only happens when meat is thawed and not in a frozen state.
Types of Curing
Curing can be performed in two ways: wet cure and dry cure.
Wet Cure: This process is also known as brining, pickling, immersion cure or sweet cure (when sugar is added). In this method dry curing ingredients are dissolved in a liquid, usually water and then meat is soaked in this solution for the required amount of time. It is traditionally used for larger cuts of meats. Wet curing ingredients include sugar, salt and flavouring. Sugar is added if the meat is cured at refrigerated temperature in order to avoid the mixture fermenting and spoiling the meat. Sugar and salt must be fully dissolved in the water/liquid when making brine.
Meat in Wet Cure
Dry Cure: Dry cure essentially is a mixture rubbed directly on the meat making sure it has evenly coated the product in order to preserve it. A dry cure is usually a ratio of 2 parts of salt and 1 part sugar by weight, to which various dry ingredients are added for flavours like black pepper, spices and herbs
Meat in Dry Cure
After the Curing process is complete, meat/fish is taken out of the dry/wet cure and washed thoroughly with cold water to remove any traces of salt on surface. After this step, the product is subjected to an air drying process to form a dry skin which is named as pellicle. It is achieved by placing meat/fish on the racks or hanging them on hooks and then subjecting them to a constant flow of cold air around them. During the smoking process, it’s the pellicle to which the Smoke sticks.
The Process of Smoking is implemented by infusing smoke in a food product which is generated by smothering wood shavings. The Aroma of smoke depends on type of wood shavings used and how long smoke is applied for. Smoke contains more than 100 compounds which includes char, ash and various gases which in turn provide the flavour to the food product. Leathery, medicinal, fruity, whisky, cinnamon, caramel and vanilla flavours can be noticed in smoke.
Sally Barns packing a mixture of Oak and Applewood for Smoking
Source: (Photographed by Sandeep Pandey at Woodcock Smokery)
Types of Smoking
Process of smoking can be divided into two methods - Hot smoking and cold smoking.
Hot smoking is the process where smoke is kept in a heated chamber of 55 degrees Celcius or above. The intention in this process is to fully cook the meat/fish. This method is not suitable for large cuts of meat as the heat or smoke can’t penetrate the core of the product. The temperature sustained in this method is lower than a conventional oven as the product must cook slowly in order to maintain moisture and absorb as much smoke flavour as possible.
Hot smoking is considered as a safer method of cooking as the hot smoke kills the bacteria while cooking the meat. Hot smoking also coagulates the proteins near the surface which creates a physical barrier which protects the element from forming mould.
Cold smoking does not cook the product but imparts flavour only. It is usually done between 10 degrees Celcius to 30 degrees Celcius . This method is purely to impart Smokey flavour and raw product can be cooked before consuming. Although in some cases cold smoked product can be consumed directly without cooking. It’s the craftsmanship of the smoker or charcutier that decides whether to air dry it further or not. Cold smoking takes longer than hot smoking – usually 12-24 hrs in case of fish and sometimes days when it comes to larger cuts of meats.
Since food is held in the danger temperature zone, rapid microbial growth may follow the process. For this reason, only meat which has been cured, pickled or fermented should be smoked. Most cold-smoked foods should undergo a cooking process with an internal temperature of 72°C before they are consumed. Nevertheless, not all cold-smoked foods have to be consumed this way. Some smoked foods can be eaten raw e.g., smoked salmon and cold smoked mackerel, which are very skillfully smoked for a lengthy period of time.
Traditional and Modern Method of Smoking
Traditional Method of Smoking:
Traditional smokehouses are built outdoors and usually with wood planks or construction material like bricks and cement. Wooden smokehouses are more popular as the wood always allows fresh air to circulate inside and the stale air to go out. Smokehouses are attached to a firebox. These fireboxes are also known as smoke generators from which a stovepipe is joined to the smokehouse wall. This layout makes it handier to cold smoke as well. Many of the old smokehouses had a dirt or clay floor on which a small smokey fire could be built. The dirt floor allows a higher humidity in winter and allows a smoldering fire to be built inside - both for smoking and to keep meat from freezing during extreme cold.
Source: (Photographed by Sandeep Pandey at Gubbeen Smokehouse)
Traditional smokehouses are windowless but do have a chimney and ventilators fitted with wire mesh. These allow circulation of fresh air and smoke (Farmer, 2011).
Figure 10: Traditional Smokehouse
Inside the traditional smokehouse, the layout completely depends on the individual depending on what product is to be smoked. In a typical setting, there is a wooden work bench and wooden roof liners where meat or fish can be hung by a claw. Some smokers use benches for heavier meats which then needs to be turned frequently in order to absorb an even quantity of smoke.
Figure 11: Inside of a Traditional Smokehouse
Figure 12: Frank Hederman in his Traditional Smokehouse
Modern Method of Smoking:
Modern smokehouses perform in a similar manner as a traditional smokehouse. The main chamber is connected with a mechanical firebox and smoke is generated by inserting wood block or shavings in the firebox. This fire box is also referred as smoke generator. Modern smokehouses come in various sizes and with different programmes which control whether the product has to cold smoke or hot smoke. It also allows to control the intensity of the smoke which in turn provides the product a stronger or weaker flavour.
Figure 13: Modern Smokehouse
Source: (Photographed By Sandeep Pandey at Baily & Kish, Howth Co. Dublin)
The Firebox in a modern smokehouse works in two different ways:
Friction Method: In this method smoke is created by rotating a rubber wheel which, when in contact with wood log, creates heat. This heat is controlled and monitored by the computer unit attached and only heats the wood up to 80 degrees Celcius which creates smoke but no fire. This smoke is then transferred into the main chamber.
(Rotating Rubber wheels)
Figure 14: Modern Firebox (Friction Type)
Source: (Photographed by Sandeep Pandey at Baily & Kish, Howth Co. Dublin
Wood-chip Firebox: In this type of modern smoker, wooden chips are dropped through a conical unit where they smoulder thorough an electric spark to create smoke which is pumped into the main chamber.
Figure 15: Modern Firebox (Woodchip)
Source: (Photographed by Sandeep Pandey at Gubbeen Smokehouse)
The compact design of modern units makes smoking much less stressful than the classic smoke houses. It’s also considerably easier to maintain and clean.
An ingredient widely known as ‘liquid smoke’ is often used to impart smoke flavour. It is inexpensive and less time consuming. It can be used on fish or meat. This product is created by gently smouldering natural wood under controlled settings and the fumes are then captured along with water vapours which are then condensed into liquid. This liquid is then stored in oak barrels to age which intensifies flavour and colour (Pearson, A.M. and Gillett, T.A., 2012). Due to the strength in flavour, only a few drops can provide a strong smokey flavour and it is used simply by brushing the liquid over the meat. It is not considered as a good creation in the culinary world because of its non-natural look and flavour although a careful and innovative use of the product can be quite useful.
Figure 8: Liquid Smoke