SMOKEHOUSE DEVELOPMENT

Old Smokehouses were impressive structures that served both as meat smokers and as storage facilities. Communal smokers were responsible for supplying meat for many families. The same was true of bread ovens. They were far too expensive for one household to own, so many shared the same one.

The main purpose of the smokehouse was not to produce cold smoke to improve taste, but to preserve it so it will last for a longer period of time. Preservation was achieved by salt curing and prolonged smoking which took about 2 weeks or more, with cold smoke. The product continued to hang in a different area of the smoker, sometimes up to two years, and during that time it lost more moisture and acquired more smoke, although at smaller rates. The meats were not cooked to an internal temperature of 160° F (72° C) because that would require strengthening the fire and the smokehouse would fill with flames. Besides, nobody knew about the effects of food poisoning yet. During that time, the lack of refrigeration promoted smoking to state of the art meat technology. Given cooling facilities, sausages would have been cooked much like how they are nowadays, quickly. There would be no need to worry about the meat spoiling, and therefore no need to develop smoking techniques for preservation purposes.

The eastern part of Poland (what is now Lithuania) became very famous for its smoked products. There was a popular square tower shaped smokehouse with a side of 6.5 foot (2 m) and 20 ft (6 m) in height. The fire pit was located outside and a trench was delivering smoke into the smokehouse. The top part of the tower contained screened openings that provided ventilation and a means for the smoke to escape. Those openings had hinged covers on the outside and allowed smoke control by serving as a damper. Due to its height and a separate fire pit, the smokehouse was able to provide natural cold smoke. This is the best possible design for a smokehouse, and is reflected in hundreds of home made smokers or industrial units. They all employ a separately standing fire pit/smoke generator.

It is not easy to improve the simple but practical design of the XV-century smokehouses. They were square chambers, with a steep chimney in the shape of a pyramid. There were no windows, just a door and screened openings just below the roof to stop insects, provide ventilation and a route to allow smoke to escape. The door had a lock to safeguard the meats from thieves and animals. Below the roof there were beams with hooks where the meat was hung. The dimensions varied from 10 – 100 sq feet of floor space and 10 – 18 ft in height.

Home Chimney Smoker

In some European homes a chimney was a part of the smokehouse. The simplest chimney design was climbing up on the roof and hanging meats on smoke sticks right on top of the chimney. The serious drawback was the meat had to accept any kind of smoke that the fire created in the wood stove.

Another solution was to attach a wooden box to the bread stove or any wood burning appliance

A much better design was placing a proper smokehouse on the second floor. On the ground floor in the kitchen a fire was burning in a wood stove. On the floor above a smokehouse was attached to the chimney. Two holes were made in the chimney: one for the smoke to enter the chamber and another to allow it to escape. On the other side a flat damper was pushed in or out of the chimney allowing the smoke to go straight up or forcing it to flow into the smokehouse.

American Smokehouses

Very similar designs were used in XVIII Century Colonial USA. During the winter in Virginia, there were so many smokehouses puffing smoke around the clock that the sight looked like a stream of locomotives ready to take off at the station. However, the fire pit was situated in the central part of the smokehouse, sometimes right on the ground. The fire was started every morning and left unattended for most of the day. Nobody worried if it went out, as it would be started again the following morning. When cold smoking, such occasional breaks are even recommended.

American XVIII Century Smokehouses

That was the simplest but the most popular smokehouse design that depended on a natural draft. It did not permit temperature, air speed, or smoke density control. There was an uneven smoke and draft distribution and blind pockets were created. In addition, hanging products acquired more smoke and soot that the rest of the batch. To compensate for that the smoke sticks and screens had to be periodically re-arranged and hung at least 5 feet above the fire. After meats were smoked for about two weeks, they were hung in a different area of the smokehouse where they remained for up to two years. They received constant smoke, but with less intensity. Thus the smokehouse functioned as a storage facility at the same time.

XVIII century smokehouses in Virginia. Those smokehouses doubled up as storage facilities where meats after being smoked for two weeks were kept inside for up to two years.

In the USA, smoking was more popular in the Eastern Parts of the country where slaves were working on tobacco and cotton plantations.The main reason was the availability and popularity of the hogs running around. Smoking and pork meat are like the left and right hands of the body.In the western parts of the country, cowboys transported cattle across large distances and looked down on any animal that wasn’t a cow or horse. The staple consisted of beef meat grilled on an open fire.

Commercial Smokehouses

Unit A - first generation multichamber smokehouse

Individual smokehouses were constructed on both sides of the chimney. That was a rather inefficient design as it required heating up not only each of the units (A) but the entire smokehouse chamber as well. Needless to say the wood usage was huge. The exiting smoke was controlled by a common to all chimney damper (5).

Unit B - improved design

A metal plate (1) was placed on top of each unit. This metal ceiling had an adjustable opening that was controlled by a flat metal damper (2). The weakness of this design was moisture gathered in the corners under the ceiling(p) which was dripping down on hanging products decreasing their looks and quality. The chimney damper was not needed anymore.

Unit C - second generation multichamber smokehouse

The next improvement was a design where each unit was independent of the others. It had a steep sloping conical ceiling (3) that provided an easier exit path for the smoke eliminating the problem of moisture pockets. The top of the ceiling was covered by an adjustable metal plate (4) that was controlled by a pull chain.

Improved design multichamber smokehouse

Improved design commercial smokehouses shared smoke exit channels that led into a common chimney. Some units could be dedicated to cold smoking and some to hot smoking as the areas were physically separated which allowed for finer temperature control. In some smokehouses each unit had its own exit channel that would enter a common chimney.

The size of the chimney was dictated by the size and the number of the individual units that shared that chimney. In most cases the front door consisted of three parts as shown in the drawing below.

Double-sided door was divided into three parts:

Bottom door-provided access to the fire pit. It had built-in dampers for air supply control.

Middle door-used for loading the fish. It had peek holes for checking progress of smoking.

Top door-used for loading the fish.

Both sides were hinged and swung wide open for easy operation of the unit.

Separate smoking/cooking smokehouse

Another interesting innovation was the design of a smokehouse consisting of two traditional smokehouses that shared a common and movable divider wall. The bottom section of the divider wall was built from firebricks (3’ high) and a metal plate rested on top of it that would be pulled up and the fish cart would travel on rails from one unit to the other.

One unit was dedicated to drying/cooking fish at high temperatures without applying smoke and the second one was for smoking only. There was hardly any fire in a second unit (smoke producer) and only little occasional flames were seen on top of the wood chips.

It should be noted that some 100 years ago a preferred method of hot smoking consisted of three stages:

Drying – 140°-194° F (60°-90° C)

Baking – up to 250° F (122° C)

Smoking – real smoking with a heavy smoke and dropping temperatures

A relatively strong and steady fire would be burning at 140°-250° F (60°-122° C) to dry/bake fish what would normally take 1-2 hours. Then the metal divider plate/wall would be raised and the cart would travel into the smoking chamber. The purpose of this unit was to produce heavy smoke which was accomplished by burning wood chips. All that was needed were small flames showing above the wood chips here and there. This process would normally last about two hours and the final temperature would be about 140° F (60° C).

That design saved fuel, time, and permitted cleaner and safer conditions in the plant. It also created well defined and separate areas of the operation:

Fresh fish preparation-cleaning, washing, brining, loading.

Drying/baking- steady fire allowing for easier temperature control.

Smoking- constant smoke generation by burning wood chips.

Cooling/packing-easier temperature control by controlling draft and using motor-driven fans.

Multilevel Smokehouses

Many three story buildings were converted into commercial smokehouses for smoking fish. A typical smokehouse would consist of:

Basement-where a firebox/smoke producer would be located.

First floor- smoke chamber.

Second floor-smoke chamber.

Normally there would be from 3-10 individual smoke chambers. All of which that were divided by a masonry brick wall going all the way from the basement to the roof. The smoke would exit through an adjustable hinged door or through rotating wind turbines. The units were about 3’6” wide and up to 15 feet long. The width was more critical as the worker was using corbells (bricks) that protruded from the wall as a ladder. He was climbing them up to hang the smoke sticks that were passed to him from another worker standing below. On each wall there were about 20 corbells separated from each other by about 5 inches. Each unit on the second floor had its own door that gave access to the smoke chamber. After opening the door a wooden board was placed on top of the beams to provide a walkway for hanging more fish inside.

Torry Kiln Smokehouse

Torry Kiln Smokehouse was a smokehouse designed in 1939 at the Research Centre Torry in Aberdeen, Scotland that revolutionised the fishing industry. It allowed for precise control of smoking parameters like air temperature, its speed, and humidity. As a result the finished product was always of the consistent high quality.

All previously built smokehouses depended on a natural draft movement (air going up) without any means of humidity control. The Torry Kiln design incorporated a motor-driven fan, electric heaters, temperature sensors, air-diffusers, and even a photo-electric eye for smoke density control.

Smoke was generated by three independently controlled fireboxes (1) that were standing above each other. Each had its own loading door and smoke damper. That provided a large smoke generating area without taking up much space. It also prevented soot and other large unburnt particles from reaching hanging fish. The smoke would enter a common duct (2) and would be deflected by aerofoils (3) towards the electric heater (4). The motor-driven fan (5) would blow the heated air through the adjustable vertical blinds (6) towards aerofoil plates (7). At the bottom of the diffuser channel the air had to pass through the inlet diffuser wall (8) that contained many individually adjustable openings for the air flow adjustment. From there the heated air or smoke would pass through loaded with fish trolleys (9). Inside the smoke chamber there was an additional booster electric heater (10). The air/smoke leaving the chamber had to pass through the outlet diffuser wall (11) that consisted of fully adjustable openings. The inlet and outlet diffuser walls allowed for a very uniform air flow in all areas of the smokehouse. At the bottom part of the channel there was a recirculation damper (12) that controlled how much air was going out to the chimney (13) and how much air was returning back towards the fan (5). Fresh air was also brought in into the same area (14). Temperature sensors (15) controlled heaters (4 and 10).