Its about time I wrote this article, I’ve been writing about pellet grills for over a decade and never got around it to. So what I want to do with this article is to explain to you in the simplest terms how pellet grills/smokers work, but then go into much more detail. You see, not every pellet grill/smoker works in the same way, and if you are in the market to purchase one there are certain features you want to look out for if your budget will allow. I’m not trying to push one specific brand over another, its more to highlight features such a PID temperature controllers, pellet hopper emptying chutes, direct flame access and stainless steel construction. However, that’s all for later in the post, first, let’s get down to basics like what actually are wood pellets and how does a pellet grill/smoker use them to produce a controlled fire to grill/smoke at a set temperature?
The Fuel: What Exactly Are Wood Pellets?
My background is actually in marketing wood pellet manufacturing equipment, its how I got into pellet grills/smokers in the first place. Wood pellets are simply a compressed form of real wood residues. I have a details article on how to make wood pellets if you are really interested. But in the simplest terms, you take real wood, chip it, dry it, turn it into sawdust, then process it through a pellet mill/press to compress the wood into pellets. Most people are familiar with animal feed pellets, well the process is (almost) exactly the same, its just the raw material which is different. I have another post on how Traeger wood pellets are made, but I’ve also included the video from Traeger below which shows the process.
Now BBQ wood pellets are not just made one type of wood. The ‘backbone’ material for making wood pellets for grills/smokers is oak, though there are lots of other hardwood species used to provide different flavours including apple, cherry, hickory etc. Softwood pellets are not used in pellet grills and smokers, softwood pellets are used in pellet stoves/boilers for heating purposes. Its not that softwood pellets won’t burn in a pellet grill, but they are not graded as ‘food safe’, and they also don’t produce a smoke taste in the food which is anywhere near as appealing.
How Does A Pellet Grill/Smoker Work? (Basic Guide)
At the start of this post, I gave a very simple explanation of how a pellet grill/smoker works (image above). This section provides a bit more detail, but its still a basic guide compared to what I’ll discuss later in this article. Now, you’ll notice I’m referencing Traeger quite a bit here. Its not because Traeger is the only brand of pellet grills/smokers, far from it. And its not because Traegers are the best choice for everyone either. However, Traeger is where the concept of pellet grills started in the 1980s, and they are still the most popular brand to this day (here’s proof). Now, not every pellet grill works in exactly the same way as Traeger’s pellet grills (as I’ll discuss that later). Heck, not even every Traeger pellet grill works in the same way. However, the general core principles of how every pellet grill/smoker works remains the same.
So as shown in the image at the top of this article, and in the video above, there are a couple of key components to a pellet grill/smoker, whether its made by Traeger or any other brand. They include the pellet hopper, auger motor, conduction/induction fan, burn pot with hot rod igniter and control panel. Let’s look at each component in a bit more detail.
The Hopper (Where The Pellets Go)
Whether you looking at a dedicated vertical pellet smoker, or a combined horizontal pellet grill/smoker, there will be a hopper for the pellets. Now the size of that hopper varies quite a lot. For instance, some portable pellet grills have a hopper of just a few lbs. Then when you get up to large pellet grills/smokers the hopper capacity can be in excess of 20+lbs. As you would expect, the larger the hopper the longer the pellet grill/smoker can run unattended. How long for? Well that depends on lots of different factors, and I’ll get into that in a future post. However, as a general (basic) rule, will you use 1-2lbs of pellets per hour going ‘low and slow’ while smoking. If you turn up the heat you will obviously consume more pellets per hour, 4lbs per hour, potentially more.
In some cases, its possible to get a pellet hopper extension to increase the pellet storage/run time of the pellet grill/smoker: Image – Amazon
The Auger (Its Just A Big Screw)
The wood pellets flow through the hopper and into an auger (a screw) which is powered by an electric motor which is connected to the control panel. When the pellet grill/smoker is first started the auger motor will feed quite a few pellets into the burn pot to get the fire going. However, once the fire is up to temperature (measured by an internal thermostat within the grill) the control panel will tell the auger to slow/stop the feed of pellets. Now, depending on the type of control panel fitted to the pellet grill, how the auger motor works does vary, more about this in the advanced guide below.
A very low geared auger motor (less than 2 RPM) turns the auger/screw to feed pellets from the hopper and into the burn pot: Image – Amazon
The Fan (To Feed The Fire/Aid Cooking Performance)
So the auger provides the pellet fuel to the burn pot. However, you also need a sufficient amount of air (specifically oxygen) for efficient combustion to take place. However, the combustion/induction fan also plays an important role in aiding the cooking and smoking performance of pellet grills/smokers. The fan helps to distribute heat/smoke around the cooking chamber, so the food cooks/smokes more evenly. The fan, like the auger, is controlled automatically through the control panel (you don’t set the fan speed independently). However, just like with the auger motor, how intelligently the fan on a pellet smoker/grill operates therefore ultimately depends on the type of control panel fitted (more about this in the advanced guide below).
This is a typical induction/combustion fan fitted to many Traeger/Pit Boss (and more) pellet grills/smokers: Image – Amazon
Burn Pot and Hot Rod Igniter (Light My Fire!)
Obviously a little reference to The Doors song there, anyway, its pretty obvious what the burn pot is for, its so the pellets and air can meet, and the hot rod igniter does its thing and you have fire! Nice and simple. Well yes, butttt, the location of the burn pot in a pellet grill/smoker can impact performance. For instance, is it in the middle or off-centre? Furthermore, is it made from stainless steel or carbon steel? Because if its just carbon steel, its not going to last forever. Also, the type of hot rod igniter used can make a difference. For instance, several premium pellet grills now use ceramic igniters as they ignite the fire more quickly and last longer.
Typical carbon (not stainless) steel burn pot fitted in previous generation Traeger/Pit Boss pellet grills/smokers: Image – Amazon
The Control Panel (Where The Magic Happens!)
Ok, so every pellet grill/smoker features a control panel. It provides the user with a simple means to turn the pellet grill/smoker on/off and to set the temperature. It ‘controls’ the auger motor, fan and hot rod igniter. However, how hot the pellet grill can get (maximum temp setting) and how accurately it can maintain that temperature ultimately all comes down to the control panel. Just how smart is it? Well, on older/cheaper pellet grills you will typically be limited to a maximum temperature of 450 degrees and a 25-degree temperature accuracy. However, on more modern/expensive pellet grills you will get higher maximum temperature settings over 500 degrees and 5-degree temperature accuracy. Why? Well, I explain more in the advanced section below.
This type of analogue/time-based pellet grill/smoker control panel perform ‘ok’. However, they are previous generation/budget technology: Image – Amazon
How Does A Pellet Grill/Smoker Work? (Advanced Guide)
Ok, I’ve covered the basics above on how pellets grills work. However, now let’s discuss what should you really want to know when purchasing a pellet grill/smoker to get something that will best suit your needs and your budget. Now, some of the topics below such as PID controllers, WiFi functionality and direct flame access are commonly found on more expensive pellet grills/smokers. However, that’s not always the case, and advanced features such as PID controllers/WiFi functionality is becoming more common, even on budget pellet grills. I have three articles if you are limited to a set budget for the best pellet grills/smokers under $500, under $1,000 and under $2,000. But for now, let’s look at how modern/premium pellet grills work.
The Different Types of Pellet Grill/Smoker Control Panels
On early generation Traeger wood pellet grill/smokers you would have found a control panel which looks very similar to the image above. However, the current generation Traeger control panels built on the D2 Direct Drive platform are very different, and I’m not just talking about how they look, I’m talking about how they actually function. I’ve covered this previously in my Traeger Pro Series Gen 1 vs Gen 2 article. Previous generation Traeger control panels where time-based. In other words, to achieve and maintain a set temperature the control panel would turn the auger/fan on and off for a certain amount of time. It does work, to a degree, however using this time-based method the actual temperature can fluctuate typically around 25 degrees from the set temperature, sometimes more.
The current Traeger Pro Series, Ironwood and Timberline models all feature similar versions of the above control panel which function on what’s called a PID (Proportional, Integral, Derivative) algorithm. With a PID control panel its constantly comparing the actual temperature inside the cooking chamber to the set temperature. A PID controller is making constant adjustments to the auger and fan speed, the result is much more accurate temperature control. Therefore, a PID controller will typically maintain the temperature to within 5 degrees of the set temperature. Hence, much more accurate than the previous generation time-based controllers.
Is It Only Traeger Who Uses PID Control Panels?
Not by any means, in fact, Traeger wasn’t actually the first brand of pellet grills/smokers to offer PID control panels. As you would expect, you have luxury pellet grill brands such as Cookshack, Memphis Grills, Twin Eagles and MAK Grills who have been offering PID control panels for many years. However, there are many pellet grills from Camp Chef, Green Mountain Grills, REC TEC and Grilla Grills who have also been offering PID controllers for many years. Weber has now also entered the pellet grill game and are fitting PID controllers, and Pit Boss is offering PID functionality on their Platinum Series.
Which Brands Are Not Currently Fitting PID Control Panels?
You will find time-based (non-PID) control panels still fitted to many budget pellet grills/smokers from brands such as ZGrills, Cuisinart, Oklahoma Joe’s and budget Pit Boss grills. Even Traeger still fits time-based controllers to some of its pellet grills, such as the Traeger Scout. However, within the coming years, you should expect to see PID pellet grill controllers become the norm.
But Do PID Controllers Produce As Much Smoke?
Now, some have reported within the pellet grill/smoker community that PID controllers don’t produce as much smoke as time-based controllers, which obviously doesn’t sound great for a ‘smoker’. There is actually some truth to this, but the results depend on the specific control panel. What a PID controller is doing is more precisely controlling the feed of fuel (pellets) and air (from the fan). Hence, you get a more efficient/controlled burn and tighter temperature control. However, with more efficient combustion you get less smoke, so what’s the solution?
Well, on more expensive Traeger models (Ironwood, Timberline) you have ‘Super Smoke’ mode, which intentionally adds inaccuracy into the PID algorithm when controlling the auger/fan. As a result, the grills temperature control will be slightly less accurate, but you’ll get more smoke. Unfortunately, that Super Smoke feature is not found across the whole Traeger range. Camp Chef, on the other hand, has introduced a 1 to 10 smoke selection feature standard across their whole range. Grilla Grills have gone for a different approach, their Alpha control panel which has both PID and time-based algorithms which you can choose from. Hence, you switch between the two to achieve either more accurate temperature control or more smoke.
Not All Pellet Grills Achieve The Same Maximum Temperatures
As I’ve referenced above previously, typically pellet grills with time-based control panels will not achieve the same maximum temperature as a PID control panels. As a PID controller achieves more efficient combustion temperatures will exceed 500 degrees (much more in some cases). Whereas time-based pellet grill controllers will typically only be able to achieve a maximum temperature of 450 degrees if that. I have a separate post on which pellet grills get the hottest. However, its not purely down to the control panel. Some pellet grills will achieve higher cooking temps, particularly for grilling/searing due to direct flame access.
Pit Boss have established a strong reputation in the pellet grill community for their grilling/searing performance due to the fact that direct-flame access is pretty universal across their entire pellet grill range. However, its not only Pit Boss who offer direct flame access. Camp Chef, Green Mountain Grills, ZGrills (in a few cases), Oklahoma Joe’s and all of the luxury pellet grill brands offer direct-flame access.
You may be wondering why not every pellet grill brand (including Traeger) currently offers direct flame access? Well, the reason is, its not risk-free as flare-ups/grease fires are more of a risk on a pellet grill than a gas grill for instance. The reason is you can pretty much instantly turn off a gas grill if a grease fire occurs. However, on a pellet grill, there is a small pellet fire going on. Hence, you can turn off the grill, but its going to take several minutes before that burn pot is empty of fuel. Check out my Weber SmokeFire article to really understand the potential issue. To improve grilling/searing performance and to reduce the risk of grease fires I often recommend a set of GrillGrates for every pellet grill.
Which Pellet Grills/Smokers Work Via WiFi/Apps? – Do You Really Need It?
Now, some regard WiFi/App functionality as a gimmick, and not something people actually need. Well, I’m not one of those people, though I don’t think anyone should choose a pellet grill primarily on its WiFi/App functionality. I discuss this more in my post on the best WiFi enabled pellet grills. I do want to quickly point out, some pellet grills come with purely Bluetooth connectivity and not WiFi. This is a big difference you need to pay attention to, as I discuss in my article linked above. Anyway, back to the topic in hand and the question do you really need a pellet grill that works via WiFi and an App on your phone?
Well, really its depends on how you will be using the pellet grill/smoker and how busy you are. If you only intend to use the pellet grill/smoker on a lazy weekend afternoon where your sat in your yard/garden 2 feet away from the grill at pretty much all times, no, WiFi is redundant. However, if your a busy person and you want to use your pellet grill/smoker as much as possible to make amazing ‘low and slow’ delicious foods, yeah, WiFi comes in very handy. So whether WiFi/App functionality is important to you is a very personal preference. However, it should not be instantly dismissed. Being able to monitor and adjust a cook while you are down the shops etc can be game-changer for many people.
So which brands are currently including WiFi/App functionality? Well, you have Traeger with their WiFire setup and Camp Chef with their Connect App. REC TEC, Green Mountain Grills and Weber all have WiFi/App functionality. Grilla Grills will be adding WiFi soon both on new models and as a retrofit option. Camp Chef was the first to offer a WiFi control panel retrofit option with their Gen 2 PID/WiFi panel.
Conclusions On How Pellet Grills/Smokers Work
I hope the above article has given you both a basic and more detailed understanding of how pellet grills/smokers work. As some people question why are pellet grills more expensive? Well, there is simply more going on inside a pellet cooking than any other type of BBQ. While they all work on the same basic principle of the pellets flowing from the hopper through an auger to a burn pot where a hot rod/fan aid combustion, there is more to it. The type of control panel fitted (time-based or PID) makes a big difference. Furthermore, whether the pellet grill offers direct-flame access or not can impact grilling/searing performance, but it also comes with the increased risk of flare-ups. WiFi/App functionality is also worth considering, but not potentially an essential feature for everyone. However, it should also not be instantly dismissed as a gimmick either.
That’s it! Thanks for reading, I hope this article on how pellet grills/smokers work taught you something new and it was an interesting read. If you would like to learn more (and there’s lots to learn) please check out my Wood Pellet Grill/Smoker Guide. 🙂