Have you ever been sitting around a fire pit, enjoying the warmth and crackling sounds it emits, when suddenly a loud POP rocks your world? You’re not alone.
● Popping noises in a fire can be caused by sap within the burning wood or gas pockets igniting.
● Choosing the right kind of wood, building the fire correctly, and managing it properly can help prevent popping noises.
That popping noise is down to various factors, including the type of wood being burned and how it is burned.
Sap within the wood can create pockets of steam, which, when heated, quickly cause a popping sound. Gas pockets trapped within the wood can also explode as they are released during burning.
In this blog post, we’ll explore the science behind fire making those popping noises and offer tips on preventing them from happening in the first place. Keep reading to learn more.
The Science Behind Fire Making a Popping Noise
Fire is one of the most ESSENTIAL and INTRIGUING elements of our world. Not only does it provide warmth and light, but it also has a unique ability to make a popping noise. This strange phenomenon is actually the result of science.
Mixture of Gases
When fire burns, it produces a mixture of gases that include water vapor, carbon dioxide, and nitrogen. These gases are heated to HIGH temperatures and expand rapidly, producing a distinctive wood pop sound.
All wood actually contains little pockets of air, but some wood types have larger pockets than others. As the wood heats up and releases these pockets, they BURST and create the popping noise we hear.
In addition to air pockets, sap within the wood can also add to the pops and cracks of a fire. As the sap becomes heated, it turns into STEAM that quickly expands and causes a popping sound as it escapes from the wood.
In addition, the gases are able to REFLECT sound waves, amplifying the noise. So the next time you hear a fire crackling, remember that there’s a bit of science behind the sound.
What Causes the Popping Noise in Fires?
There are MULTIPLE reasons why a fire might make popping noises. It’s important to understand the causes in order to prevent them. Let’s take a closer look at the main culprits:
Type of Wood
Any experienced camper knows certain types of wood should NEVER be used for a campfire. For example, pine and cedar (softwood logs) contain HIGH LEVELS of sap. As the fire burns and heats up the sap, it turns into steam, creating pockets that quickly expand and pop.
The result is a shower of sparks that can easily start a forest fire. Even if you’re lucky enough to AVOID starting a blaze, the popping and crackling noises of the sap can be extremely annoying.
For those looking for a peaceful camping experience, it’s best to stick with low sap-content wood to MINIMIZE popping.
Hardwoods like oak or hickory burn SLOW and STEADY, providing steady heat and minimal wood pops. So next time you plan a camping trip, be sure to bring along the right type of wood.
Pro Tip: Kiln dried wood has lower sap content, making it a great choice for campfires.
Moisture In The Wood
Wood that hasn’t been properly dried or seasoned can HOLD EXCESS moisture inside, producing steam during the fire-burning process. This trapped moisture creates pockets that pop as they heat up, causing cracking and firewood pops.
Unseasoned green wood should NEVER be used for a fire, as it produces not only popping noises but also smoke and poor heat output.
Kiln-dried firewood is the least moist firewood to use on your fire. Kiln drying removes moisture from the wood using high heat, resulting in a clean burn with minimal pops and crackles.
According to the United States Environmental Protection Agency, the best firewood is aged for at least six to twelve months before fire burning. This allows time for the moisture to evaporate, resulting in a better burn and less popping. 
You can check the moisture content of your wood using a moisture meter. This device measures the wood’s moisture content, ensuring it’s ready for fire burning.
Another way to ensure dry wood is by storing it in a covered, elevated location away from rain and snow. This allows airflow to continue removing excess moisture from the wood before use.
Pro Tip: To ensure your firewood is properly seasoned, always buy from a reputable source or allow the wood to dry out before using it.
Proper Fire Building
Building a fire CORRECTLY is key for a variety of reasons, including avoiding irritating popping noises. When stacking the wood, make sure to leave ample space for airflow.
Piling the wood too tightly can lead to fresh oxygen being cut off, causing the fire to smolder and produce steam pockets that pop. Instead, build a tepee or log cabin-style stack to ALLOW for proper air circulation and prevent popping noises.
The Fires Efficiency
Managing the fire properly is also IMPORTANT for preventing popping noises. Keep the flames steady and controlled to prevent excess steam buildup.
Avoid poking or prodding the logs, as this can break apart steam pockets and cause them to pop. Maintaining an EVEN FLAME will also ensure the wood is burned efficiently, resulting in a longer-lasting fire.
How to Prevent Fire from Making a Popping Noise
Making sure your fire is well-ventilated is important for many reasons. One reason is that it prevents the fire from making a popping noise.
When there is not enough oxygen flowing into the fire, the wood will pop and crackle as it burns. Oxygen is essential to help the fire burn. It’s what keeps the combustion process going.
According to the United States Forest Service, building a fire with enough space between the logs and not piling it too high will allow for proper oxygen flow and minimize popping noises. 
This can be annoying and also potentially dangerous, as flying sparks could start a new fire. To PREVENT your fire from making a popping noise, ensure no obstructions are blocking the flow of air to the fire.
This includes removing any ashes that have accumulated in the fireplace and keeping the flue open. In addition, you can add a layer of sand to the bottom of the fireplace, which will help to ABSORB any sparks that come out of the fire.
By following these simple steps, you can help to ensure that your fire burns safely and evenly.
Frequently Asked Questions
Does Seasoned Firewood Pop Less?
Seasoned firewood has had time to dry out and release excess moisture, which can cause popping noises in the fire. So yes, seasoned wood will typically pop less than unseasoned wood or green wood. 
Can Popping Firewood Be Dangerous?
Popping firewood can be DANGEROUS as it may result in flying sparks that could potentially start a new fire. It is important to manage the fire to prevent excessive popping and cracking.
Can Adding Water to a Fire Cause Popping?
Adding water to a fire can cause it to pop and crackle as the water turns into steam and creates pockets in the burning wood. It is best to AVOID adding water to a fire.
So the next time you’re enjoying a cozy campfire, remember that there’s a bit of science and technique involved in avoiding those pesky popping noises.
Choose properly seasoned firewood, build your fire with ample space for airflow, and manage the flame to prevent excessive popping. Happy burning!