How to Control Temperature on a Charcoal Grill

charcoal grill with vents for adjusting temperature

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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.

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:

  1. Place all your coals to one side of the coal grate
  2. Spread them evenly across ½ to ⅔ of the area
  3. Replace the cooking grate

The area that is directly above the coals is now your grilling or direct cooking area, and the area away from the coals is used for in-direct cooking.

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.

If you are wondering how much charcoal you need in your hot zone, we share some tips in a separate post on the matter.

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 intake dampers. They provide airflow to the coals.

weber kettle charcoal grill with a closed lid
The exhaust vent on top of a Weber Kettle grill

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:

  1. Leave the exhaust damper on the lid fully open and control the airflow with the bottom intake damper
  2. Do the opposite, as Weber recommends and leave the bottom damper fully open and control temp with the lid exhaust damper

At 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.

  1. Simply grab some foil
  2. Fold it over two or three times
  3. 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 set up a grill for smoking 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:

How2BBQ™ Video#3 Charcoal setup for slow and low. Minion Method explained.

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 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.

Direct Cooking:

If you plan to cook something for longer than 30 mins over direct heat:

  1. 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.
  2. Spread unlit coals evenly on one side of the coal grate.
  3. Place the lit coals evenly amongst the unlit coals.
  4. 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.

Indirect Cooking:

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:

  1. Place the unlit coals in a pile on one side of the coal grate
  2. Place the five lit coals close together in the centre of the pile of lit coals
  3. Place the food on the opposite side of the cooking grate to the pile of coals
  4. 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.

When it’s time to shutdown your grill when you are finished cooking, you simply need to close all the vents down.

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!

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