How to Control Temperature on a Charcoal Grill
Do you have a friend with a charcoal grill sitting in the corner of the garage collecting dust and cobwebs?
Or maybe you’re the owner of a badly neglected grill.
While many excuses are thrown around, the main reason people give up on their charcoal grill are due to an inability to control the temperature.
The ability to hit to maintain and just temperature throughout the cook are crucial skills to avoid overcooked, undercooked, or all out charred grilling disasters.
Unlike gas grills, charcoal grills require some skill to control the temperature. But if you learn the right techniques, with a little bit of practice you can master the art of temperature control and start impressing your friends and family with your caveman skills.
Click to jump straight to each topic
- The four ways to control heat
- Controlling temperature during ‘Low and Slow’ cooks
- Wrapping it up
- How to use Air Vents to Control Smoker Temperature
- The Correct Way to Adjust Smoker Temperature
- Always do a ‘dry run’ on a new smoker
- What to do if You See Thick, White Smoke?
- How the weather can effect your smoker temp
- Turn your charcoal smoker into a ‘set it and forget it’ smoker with an automatic temperature controller
The four ways to control heat
There are really just four techniques involved in effective temperature control. Get a handle on them, and you are well on your way to grilling greatness.
Depending on how you use your grill, you’ll probably end up relying mostly on one or two of these methods. Even so, it’s worth knowing every option.
1) Build a Two Zone Fire
By creating a hot zone for searing and, and a “cooler” zone for indirect cooking, you can take control over how well cooked your meat is simply by moving it to the correct side of the cooking grate.
To build a two zone fire:
- Place all your coals to one side of the coal grate
- Spread them evenly across ½ to ⅔ of the area
- Replace the cooking grate
The area that is directly above the coals is now your grilling, or direct cooking area.
Here’s how it looks:
If you want to stop grilling your food, or wish to cook it indirectly, simply move the food across to the side of the grate without coals underneath.
Food sitting in the indirect cooking zone will be cooked by convection, that is, warm air circulating around the food. This will result in even cooking of the meat both inside and out, not just on the surface.
2) Increase or decrease airflow by adjusting your grill vents
Here is the simple rule of thumb:
When cooking with charcoal, more airflow = hotter grill
This is the opposite to gas grilling, where opening the lid will just let heat escape.
It is especially important to keep all the vents opened fully when starting your grill. To get the coals glowing they need plenty of oxygen.
Grills have vents at the bottom and the top. The bottom vents are called the intake dampers. They provide airflow to the coals.
The vents at the top are called exhaust dampers. These vents take the smoke away, like a chimney. In doing so, they suck air through the grill, so keeping them open encourages airflow through the entire system.
So should you adjust the bottom intake damper or the top exhaust damper?
There are two main schools of thought:
- Leave the exhaust damper on the lid fully open and control the airflow with the bottom intake damper
- Do the opposite, as Weber recommends and leave the bottom damper fully open and control temp with the lid exhaust damper
At AmazingRibs.com they recommend the first option.
Meathead Goldwyn, Using the Vents to Control Temperature on Charcoal and Wood Burning Grills and Smokers
“As you try to master your cooker and calibrate your system, you are best advised to leave the exhaust damper open all the way.
Do some dry runs without food, play with the intake vent only, and try to hit the marks called for in almost all of my recipes: 225°F and 325°F.
You should not play with the exhaust vent unless you are unable to hit those temps by adjusting the bottom vent alone.
Playing with both vents at once is like trying to control the speed of your car by using both the gas pedal and the brake at once.”
Both approaches will work, and it’s up to you to experiment. We prefer leaving the exhaust damper open and adjusting the intake damper.
Either way, you should not completely close off the exhaust damper (top vent) when cooking, as the smoke and gases need to escape.
3) Adjust the distance between your food and the coals
The closer your food is to your coals, the hotter it is and the faster it is going to cook. I realize this is not rocket science, but getting to know where the ‘sweet spot’ is will take some trial runs.
Some grills have adjustable cooking grates which make life easy. Just move the food further away if you feel it is getting too hot, and visa versa.
If your grill does not have this handy feature, there is a way around it. Use the first technique to create a two (or more) zone fire. Then you can move your food between the hot or cooler parts of the grill as needed.
4) Use a Grill Shield
If things are cooking quicker than expected and you need to do something about it fast, you can make a shield of aluminum foil to block the heat.
- Simply grab some foil
- Fold it over two or three times
- Slip it under the piece of food that is about to burn.
This method will not stop the food from cooking completely, but by blocking the amount of radiant heat that is hitting your food, you will slow the process down a little.
Controlling temperature during ‘Low and Slow’ cooks
The four methods described above will work great when grilling at high temperatures.
If you want to use your grill as a smoker, there are some additional tactics worth knowing. The key to successfully cooking low and slow on a grill is largely in the setup.
How to setup your grill:
The most common way to setup a grill for long cooks and low temperatures is the minion method.
The minion method involves lighting a smaller amount of coals, then adding unlit coal. The lit coals then gradually light up the unlit ones.
This is what it looks like:
The logic behind using this method is as follows:
If you put a whole chimney load of lit coals in your grill, the temperature is going to start quite high and you will be struggling to bring it down before you can even start to think about introducing food.
With the minion method your grill can quickly reach the perfect smoking range of 225-250°F and then stay there for many hours.
You can still use a charcoal chimney to light your coals when using the minion method, just flip the chimney and use the smaller chamber to light the coals.
Another popular option is the Snake method, which we discuss in more detail in this guide.
Indirect vs Direct
You can cook low and slow on a grill using both the direct and the indirect cooking method.
Whichever way you want to cook, you need to look at things a little differently:
Lit coals are the heat source, and unlit coals are the fuel source.
Lets see how to put this into practice when cooking both directly and indirectly.
If you plan to cook something for longer than 30 mins over direct heat:
- Light enough coals to bring the grill up to the desired temperature. Usually around five lit coals will get you up to 225-250°F.
- Spread unlit coals evenly on one side of the coal grate.
- Place the lit coals evenly amongst the unlit coals.
- Place your food above the coals and put on the lid. Replacing the lid will control the airflow and stop the coals from burning too hot.
By spreading the coals out evenly, and reducing the number of lit coals, you food will cook evenly and will not burn, even if it is cooking for some time.
For most low and slow cooking, you’ll want to setup for indirect cooking.
To cook indirectly on a grill you still need to control the amount of lit coals you use. Again, about five coals will mean your grill sits at a temperature between 225-250°F. The set up is a little different to cooking over direct heat though:
- Place the unlit coals in a pile on one side of the coal grate
- Place the five lit coals close together in the centre of the pile of lit coals
- Place the food on the opposite side of the cooking grate to the pile of coals
- Replace the lid
If you need to cook for longer, increase the amount of unlit coals. If you want to cook at a higher temperature, increase the amount of lit coals.
Tip: Take advantage of both indirect and direct heat when cooking a thick steak, for instance, by trying the reverse sear. Bring the inside of the steak up to temperature using indirect heat, then move it over to finish off with direct heat and get a nice crisp exterior.
Don’t get trigger happy adjusting your vents
You can still control the temperature by adjusting the vents. However, you should wait until the temperature has been stable for around 20-30 minutes before you start fiddling with them. That way you know what your starting temperature is.
Similarly, if you have adjusted the vents, allow around 20 minutes for the temperature to reflect the change.
You will need to experiment a little with your grill to see what vent settings work for you. Some home grillers have found that setting both top and bottom vents to half is a good starting point.
Wrapping it up
Using a charcoal grill does not mean that all you can do is sear steaks and flip burgers. In fact, there is not much you can’t cook on a grill.
The secret lies in being able to control the temperature of your grill. Once you have some techniques down pat and some basic knowledge about how temperature control works, the sky’s the limit as to what you can cook on your grill.
We hope you have found this article helpful, and you feel enthused to head out and try some of the techniques on your grill this weekend.
Do you have any tried and true techniques that work to control the temperature on your grill? Or are there still some ‘burning’ questions you would still like answered that were not addressed in this post? Please be sure to let us know in the comments section below. And if you found this article useful, be sure to share!
How to Control Temperature on Your Charcoal Smoker
For those of us who still cook with charcoal, temperature control is one of the most fundamental skill we need to master. Many any amateur pit master has fired up their brand new smoker and ended up wasting perfectly good meat because they didn’t know how control their temps.
But don’t worry. With a basic understanding of how the science of heat works you’ll be equipped with all the knowledge to go out and master your pit.
And then you can join the proud tradition of looking down on people who cook on the much easier gas, electric or pellet grills.
How to use Air Vents to Control Smoker Temperature
A steady smoking temperature is necessary for fully cooked, tender, smoked meats. For most low and slow cooking, that means we need to know how to get our smoker to between 225 – 250°F and then keep it there for 4 – 16 hours.
There is much more to temperature control than loading up the firebox. Knowing how to make the most of your smokers air vents is key.
Most smokers have two types of vents, one at the bottom and one at the top, although smoker designs do vary. The bottom vent, located near, and usually under, your firebox is known as your intake vent. The top vent, is your exhaust vent. Air comes in your intake vent. Warm air circulates from your fire box out the exhaust vent. Because hot air rises, your exhaust vent acts as a vacuum to draw air into the intake vent. When this hot air rises, it heats up your smoker.
Meathead goes into more detail into how the intake and exhaust work over on amazingribs.com
Meathead Goldwyn, Using the Vents to Control Temperature on Charcoal and Wood Burning Grills and Smokers
The intake damper is near the charcoal or wood and its job is to provide them with oxygen. The intake damper is the engine that drives the system. Close it off and you starve the fire and it burns out even if the exhaust damper is open. Open it all the way and the temperature rises. On most grills and pits you control temperature mainly by controlling the intake damper.
The exhaust damper (a.k.a. flue, vent, or chimney) has two jobs: (1) Allow the combustion gases, heat, and smoke to escape, and (2) pull oxygen in through the intake damper. This pull, called draft, is created by hot gases rising through the chimney trying to escape.
The exhaust damper needs to be at least partially open at all times in order to keep combustion gases from smothering the fire like a wet blanket of CO, CO2, and other combustion products.
The Correct Way to Adjust Smoker Temperature
So we know that the way to control your temp is by adjusting the intake dampers. But before you go opening and closing them and overshooting the mark a word of caution. The best explanation we’ve heard for this comes from the folks over at Geek With Fire.
A smoker’s firebox and vent system can be compared to a large truck with a small engine. It is going to take some time to get the truck up to speed. However, once you get to speed, it is even harder to slow down due to gravity, momentum, and the size of the truck.
Just like the metaphorical truck, a smoker takes a while to reach your desired temperature. Once your temperature begins to rise, it can go rapidly. When you do reach that temperature, you will have a hard time going back down. This is called an overshoot. You don’t want to overshoot your target temp.
It is important to remember to make minor adjustments BEFORE you need to. This will help you avoid overreacting and overshooting the temperature you were trying to reach.
Here are some factors to keep in mind when adjusting the intake damper
- Make note of how fast your temperature is rising. The faster it is rising, the sooner you need to take action.
- Want to back off your temperature? Adjust your intake vent to a more closed position. This will let less air in to heat up your smoker causing the temperature to rise at a much slower rate.
- Feel like your smoker just isn’t hot enough? First, ensure you still have enough charcoal in your fire box. If you’ve been running your smoker for several hours a gentle stir may be enough to get back up to temp. Sometimes you just need to add more fuel though.
- Avoid over adjusting your vents. When you make an adjustment, give it plenty of time to work before adding another adjustment.
Always do a ‘dry run’ on a new smoker
Our primary aim here is to not blow an entire pay check on ruined meat. The best way to do this is to make sure you have full control of your barbecue at all times. This means you know exactly how to get it to a safe smoking temperature between 225 – 250°F, and how to hold it there.
It also means you know how to make adjustments when things go wrong.
Malcolm Reed of HowToBBQRight recommends taking your smoker on a trial run before loading it up with meat. This makes a lot of sense. All smokers work a little differently. The time it takes for different smokers to reach your target temp varies.
While most smokers come with a built in thermometer, these can be up to 50°F off the actual temp where your meat will be sitting. This is why we always recommend using a dedicated thermometer to keep track of your temps. Even during a dry run it’s well getting in some practice.
You can take notes about how long it takes for your smoker to get up to temp. You can then pay careful attention to how your vents work, and how adjusting them slightly can result in large temp swings.
What to do if You See Thick, White Smoke?
Thick white smoke is an indicator that your wood isn’t burning properly. Ideally, the smoke coming from the exhaust vent should be thin and blue in color. Thick white smoke will impart an undesirable, bitter flavor to your meat. Damp wood is commonly said to be the culprit when thick white smoke is present.
- If you can help it, avoid using damp wood.
- Adjust your intake vent to allow more air flow.
- An increase in air flow will help ensure a hotter fire, therefore your wood will combust and burn quicker.
How the weather can effect your smoker temp
Weather is always a factor when smoking. This can be an even bigger factor if you are cooking with a cheap or poorly insulated smoker. A windy day will cause more air to flow through the intake vent, causing a hotter fire.
Cold weather outside can also cause you to loose more heat through the walls of your smoker. Always keep more fuel on hand than you usually would.
Smoking isn’t just a summertime activity though so you shouldn’t let bad weather put you off. Just be sure to account for wind ideally by placing your smoker in a sheltered position. You may also want to close your vents off slightly more than usual.
Turn your charcoal smoker into a ‘set it and forget it’ smoker with an automatic temperature controller
So far we’ve learnt how you can control the temp in your smoker by adjusting the air vents to achieve your desired temps. While this can achieve relatively reliable barbecue low and slow temps, you’re always going to get the occasional flare up. All it takes is a change in the wind direction (especially if your smoker is on the leaky side) and you can experience a dangerous heat rush.
Rather than baby sitting your smoker all day (and potentially all night), some very clever people have invented a device to do this for you. These automatic temperature controllers work by connecting to your smoker and then regulating the air flow to maintain a steady temperature. They take the guess work out of constantly adjusting air vents.
For those of you who like to stay warm and comfy in side (or in bed) while your food smokes, these units are a life saver. The WIFI connection allows you to keep an eye on the temperature and even adjust your desired temp on the fly. These units also come with more features that let you produce logs and graphs to impress your geekier barbecue mates.
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Wrapping it up
After reading this guide you should feel confident using the vents on your smoker to control your temperature. There’s no substitute for practice though! The best thing you can do is experiment with your new smoker in a variety of different conditions to get a feel for it.
If you are cooking on a Weber Smokey Mountain there is a fantastic guide to all the factors that might be making your smoker run hot or cold. Otherwise let us know in the comments below if you have any tips or suggestions you think we’ve missed for controlling your temps.