There isn’t anything on planet Earth that’s like using an offset smoker to create mouthwatering bbq meals.
The combination of smoke and fire that combines to create such delectable morsels as bbq smoked brisket and low and slow pork shoulder is heavenly, but only if you can control the fire in your pit.
You see, maintaining a consistent temperature over an 8-16 hour long cook isn’t just science, it’s an art form. In this article, we’re going to show you how you can maintain a super steady fire in your offset to create that bark and smoke ring that you’ve been gunning for.
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Offset fire management can be tricky, even if you’ve done it many times before.
There’s charcoal, wood splits, intake and exhaust dampers, outside temperature, thickness of the metal of your smoker, wind, rotation of the Earth, and how you hold your tongue to consider… Well, maybe not those last two, but the sum of it all can be overwhelming!
How Do You Control The Temperature On An Offset Smoker?
To control the temperature on an offset smoker, you need to manage two primary things, airflow and the size of your fire. Airflow is controlled by the size of the opening you leave on your intake and exhaust vents. The size of the fire is controlled by how much wood and charcoal you have active in the offset firebox.
To better understand how to control your fire, let’s start with the science of fire management.
How Does An Offset Smoker Work?
An offset smoker works by creating a fire using charcoal or wood in an offset firebox that exists outside of the main cooking chamber of the grill. An air intake vent allows oxygen into the offset firebox which supplies a critical component of fire. The intake of air flows across the fire and into the main cooking chamber drawing smoke and heat around the waiting food.
Heat, fuel and oxygen are required for the fire event, and the intake damper of an offset smoker controls the critical supply of oxygen to determine the size of your fire.
If you close the damper down all the way, it restricts the flow of oxygen and chokes out the fire. Open the damper all the way, and the fire has unlimited oxygen for fire and it can quickly get out of control.
The art of offset smoker fire management comes when you understand how your particular smoker reacts to fire size and allowed oxygen amount.
What is the Perfect Fire Size for an Offset Smoker?
Aah, don’t you wish it was that easy? There is no perfect fire size that fits every offset smoker. There is a perfect fire size for your smoker though, and here’s how to find out what it is.
Start by lighting up a chimney of lump charcoal to get things started. Lump charcoal tends to burn hotter than charcoal briquettes, and with this chimney of coal we’re looking to jumpstart the smoker and get it up to temperature.
We like to use tumbleweed fire starters to light our fires here at The Barbecue Lab, and our favorite lump is Rockwood charcoal. If you haven’t yet picked up a charcoal chimney, the BBQ Dragon and the Dragon Fan is one of the coolest bbq toys we’ve seen in years. It lights up charcoal in only about 3 minutes instead of 20+ minutes, and we love it here at the lab.
What you’re looking to learn here is how hot a single chimney of charcoal will get your offset. Dump the lit charcoal into the firebox and close the lid. For the intake vent, go ahead and leave it wide open on the firebox and the same goes for the exhaust vent on the smoke stack.
Here’s where the patience comes in. Set a timer for 30 minutes and don’t fuss with it. Just let it warm up and see how hot it gets. We’re going to call this your smoker’s baseline level.
Maybe your smoker will get up to 200 degrees, and that’s just fine. For others, your smoker might get up to 350 degrees. Great! The final temperature isn’t important for our purposes, and a higher temperature at this point doesn’t necessarily mean that your smoker is better or worse, it just is what it is.
Whatever temperature your smoker gets to with one chimney of charcoal after 30 minutes, it’s time to think through how to get your smoker to 275 and get it to hold for an hour.
For those of you sitting at 225, it’s time to add a split of smoking wood to the top of the coals. If you’re one that had your grill hit 350 on a single chimney, then next time it’s time to start with a half a chimney and see where that takes you after 30 minutes.
I’m sure some of your might be wondering why 275 is our target temperature for this test. We’ve learned over the years that 275 is a sweet spot for everything from brisket to pork butt to ribs. It’s the temperature that we work to maintain for most of our cooks that we do on an offset smoker.
You’re absolutely welcome to pick another temperature number for your test, but for the remainder of this article, we’re going to aim for 275.
If you added a split of wood to the top of your charcoal, you probably noticed that it didn’t light straight away. That’s because the log hadn’t “warmed up” and it took a few minutes to get the log to the heat level where it could combust.
This is where we suggest a particular way of lighting your fire in an offset to allow you to warm up logs in your firebox. In our Lone Star Grillz 24×48 offset, we always set our fire against the wall of the firebox that’s away from the side we can get into. For the Lone Star, that’s on the right side of the firebox since the door opens to the right.
By building the fire on the far side of the firebox, we leave room to place an unlit log on the far left side of the firebox to warm up. As the last log that was placed on the fire turns to embers, the log on the left side of the firebox will already be warm and take just a few seconds to combust after being placed on the coals.
Replace the log on the left every time you place the warmed up log on the fire, and you’ll eliminate the thick white smoke that comes off a log that hasn’t been warmed up.
Thick White Smoke Vs. Thin Blue Smoke
Wait, we want smoke though, right? That’s the whole reason that we’re doing this in the first place?
Yes and no. The whole point of smoking food is to impart a smoky flavor and smoke ring, and that is best accomplished by thin blue smoke instead of dense white smoke.
Dense white smoke will bring a bitter taste to your food while thin blue smoke infuses smoky goodness into your meal. For years, even competition bbq cooks would try to keep all of the thick white smoke in their cookers to get as much smoke on the meat as possible, but we’ve learned a better way.
When we run our Lone Star, we always run it with both dampers wide open. We want maximum airflow to be able to get to the fire and carry thin blue smoke across our meat and out the exhaust.
The more we choke down our fire, the more dense the smoke gets and the more bitter our meat will taste. We find that the more open we can keep things, the better the smoke ring and the smokier the meat.
So, back to the test. Our goal is to figure out what it takes to get and keep your smoker at 275 degrees with the intake and exhaust vents open. This process is for an offset smoker and not a kamado grill as they work differently and need a different fire management method.
Record how hot your pit gets after a chimney of charcoal, after adding a single split of wood and after adding two splits of wood. Check the sizes of the splits of wood because not all splits are made equal.
Some splits are simply a log quartered while others are a log split 8 ways. There’s also the size of the split to consider as very large logs split 8 ways can still be huge.
The secret to good and consistent fire management is knowing what amount of fuel your pit requires to achieve your desired temperature.
For our Lone Star Grillz unit, we take two full chimneys of lump charcoal and add them first while immediately adding our first split of wood. This will get our cooker up to 275 for 45 minutes before we need to place another log on the fire to maintain temperature.
There’s nothing like experience when it comes to maintaining a consistent fire on your offset, so set a time this weekend to light a fire with plans to cook nothing, and I’m sure you’ll be glad you did.