Smoking is the process of flavoring, cooking, browning, or preserving foodstuff by exposing it to smoke from a smoldering material, like hardwood.
Smoking is achieved by placing the foodstuff inside an apparatus called a "Smoker." The Smoker works to trap the hardwood smoke and expose the foodstuff to compounds like char, creosote, ash, phenols, gases, as well as liquids (water vapor, syringol, and guiacol).
In order to produce smoke you need: oxygen, combustible fuel, and fire/heat source. When all of these elements are introduced, combustion occurs. For smoke to occur, the oxygen and the heat are adjusted so that the combustible material smolders which results in visible smoke.
Note: Most of the flavor components actually come from gases, not smoke. The composition of gases depend on the oxygen and temperature.
Read More: Thin Blue Smoke Explained
The above information is important to understand because the apparatus or smoker has a direct effect on smoke.
Smokers are categorized primarily based on their interaction with the heat source; It's either described as "direct" or "indirect." They are also categorized based on how they produce heat (hardwood, charcoal, electricity, pellets, etc).
Offset smokers are comprised of a firebox, a smoke/cook chamber, and a smokestack.
As the name suggests, a "stick" burner relies solely on hardwood as their fuel source. They are also called "offset" smokers as the fire or firebox is built in one chamber and the smoke/heat crosses the food in another (the firebox is offset from the cook chamber).
In a traditional offset smoker, the firebox produces the heat and smoke which travels across the meat in the smoke chamber, and then exits through the smokestack on the opposite end.
The smokestack on an offset smoker can also be setup to "reverse-flow." A heat baffle set below the grate causes the smoke to travel below the baffle and across the meat in the opposite direction. The smokestack is also placed perpendicular to the firebox.
The benefits of reverse-flow being:
While technically a stick burner could use charcoal as a base and then use hardwood to impart flavor, the purpose of these smokers is to use only hardwood (sticks). Fire management requires a rather steep learning curve and near constant attention.
Charcoal smokers are a smoking apparatus that use charcoal as the primary fuel source (typically in the form of briquettes, as lump charcoal burns too hot for smoking). Hardwood is then added in the form of wood chunks and chips to help impart flavor (most of the smoke is actually from the charcoal).
The charcoal smoker category includes a number of different types of smokers. Including but not limited to Bullet Smokers (Weber Smokey Mountain), Drum Smokers (Pit Barrel Cooker, Gateway Drum Smoker, DIY), and ceramic Komodo ovens (Komodo Joe, Big Green Egg, Primo).
Charcoal smokers are typically comprised of a charcoal basket/firebox, a water pan(not all feature a water pan), cooking chamber, and a lid.
The firebox is where the briquettes or lump charcoal are contained and where wood chunks or wood chips are added to produce smoke.
The water pan (chamber) is positioned above the firebox and is filled with water. The water pan serves two purposes: helps to maintain lower temperatures , and to add moisture via water vapor (the same reason people Texas crutch - combats moisture wicking properties of meat).
The cooking chamber is where the meat is placed to smoke.
The lid caps off the environment and prevents smoke from escaping. The lid usually has a vent to allow smoke and steam to escape and may even feature a temperature gauge.
Note: A number of brands sell charcoal smokers that market themselves as a traditional grill with a smoking component; You may even see them referred to as smoker grills as well as "water smokers."
Temperature control on a charcoal smoker/grill is done by:
Personal side note: The Weber Kettle was one of the first grills I ever owned. I still use it to this day to cook hamburgers and hot dogs. Kettle grills last a long time because they have no moving parts and Weber doesn't skimp out on materials. Technically a kettle grill can be made into a smoker through the use of strategic charcoal arrangements (like the snake method pictured below) and a water pan.Dylan Clay
A pellet smoker (or grill) is similar to that of a kitchen oven, it's thermostatically controlled; Plug it in, set a temperature, and the smoker cooks the food.
Pellet smokers are typically comprised of a hopper, an auger mechanism, a firepot, combustion (intake) fan, heat baffle and deflector (drip-pan), a cook chamber, and smokestack.
The hopper is where the food-grade pellets are contained. The hopper functions as storage for the pellets and helps to gravity-feed the auger. The auger works via a motor/electricity to pull pellets into the firepot. The firepot features an igniter rod that ignites the pellets which are then fed with oxygen via an intake fan. The baffle and deflector (drip-pan) create a convection of heat that then cooks the food. The smoke/heat then exit the apparatus via the smokestack (and to less of a degree via the drip pan/trough).
Smoke is introduced via food-grade wood pellets. The pellets are most often created by pulverizing and drying hardwoods. The saw-dust is then compressed under a heated and pressurized environment. The pellets shape is a by-product of the lignin content in the wood.
"Food-grade" pellets are different from pellets used for household furnaces/stoves as they often contain a gluing agent that helps to bind the pellet materials together (not safe for human consumption). Pellets for stoves/furnaces are also made of forest waste which often contains bark; Bark content spikes BTU output.
Pellet smokers typically have two modes of function or "controllers"; These are often referred to as PID and Non-PID controllers.
PID or proportional-integral-derivative is a control mechanism that is used in a wide variety of industrial control systems. You set a point or temperature and the controller will monitor a measurement (Process Variable or PV). The controller attempts to maintain the PV based on the Proportional Integral Derivative terms of an equation.
In more practical terms a PID controller will automatically apply an accurate and responsive correction to a control function (temperature). Meaning in a pellet smoker the PID controller will slow the rate at which pellets are fed to the smoker as temperatures approach the control (225°F, 250°F, 275°F, etc.). Most brands will advertise accuracies of +/- 5 degrees Fahrenheit.
In contrast, a non-PID controller will simply dump pellets until the smoker reaches the control and then stop. This causes the temperature to overshoot the control and then come back down below the control resulting in a temperature swing of +/- 15 to 20°F. The purported benefit being more smoke output.
Personal disclaimer and word of caution to people looking to buy pellet smokers/grills: While I personally love my pellet smoker, they are relatively new in terms of offerings. Traeger's original patent on the pellet grill expired in 2006 meaning more marketing hype and gimmicky terms are used to describe a number of the things I've outlined above. Do your best to wade through these things as most function in the exact same way only they are marketed/advertised with fancy terms to entice your purchase.Dylan Clay
Electric smokers feature a cooking chamber with cooking racks that are vertically oriented, an electric heating element, wood chip tray (and tube), water pan, and dampers/vents.
Heating elements like the ones in electric smokers work through the conversion of electrical energy into heat through Joule heating; The electric current passing through the current is met with resistance, which produces heat. In electric smokers, the heating element is typically made of stainless steel as it's resistant to oxidation, corrosion, and wear.
The "wood chip tray" is affixed above the heating element which causes wood chips to smolder. In order to help minimize the opening and closing of the cooking chamber, a "wood chip tube" is used to drop wood chips in the tray (pictured left).
Similar to charcoal smokers, the water pan is used to help add humidity to the environment. However, since opening the cooking chamber essentially lets all the heat out, the water also helps to add thermal mass. Meaning the smoker has an easier time returning to the pre-programmed temperature.
A personal side-note: My Masterbuilt electric smoker was one of the first I ever bought. I still use it to this day to smoke beef jerky and to make beef sticks. In terms of consistency at lower temperatures, they're VERY hard to beat. White (dirty) smoke is a common problem with electric smokers and it usually boils down to not enough heat or not enough oxygen (learn more about clean smoke).Dylan Clay
Gas smokers make use of either natural gas or propane as a fuel/heat source and wood chips are then used to add flavor.
There are two main types of gas smokers used:
The first being a similar chamber setup to that of an electric smoker; The difference being the heating element (propane burner). The cooking racks are vertically oriented and the heating element ignites the wood chip tray. A damper is then used to help exhaust steam and smoke.
The second type isn't actually a smoker, it's a grill. However, smoke can be introduced via wood chips or food-grade pellets being placed inside a smoke box/tube. The box/tube is then placed on flavorizer bars and smoke is allowed to build in the environment.
The question then becomes, which is best? This is super hard to state as all of these categories have their own applications and limiting factors.
For instance, do you have close proximity to an outlet? If not, a pellet or electric smoker isn't feasible. If you do, what do you plan to cook? Pellet smokers have more capacity than electric smokers, however electric smokers can put out great ribs as well as pork butt easily.
What sort of budget constraints do you have and what's your experience level? If you have the experience and the money then a stick burner should be considered as it's the traditional way barbecue is made. However, they can cost an arm and a leg.
In my opinion, charcoal smokers are a good medium in terms of cost of the smoker and learning curve (as low as ~$165 for a Weber Kettle and an upwards of $800 for a Gateway Drum). In most cases they're as simple as determining how much charcoal to use and then adding wood chunks.
However, any of these options can put out great barbecue. Your choice really boils down to experience, budget, and personal preference.