Do your fires constantly pop and crackle? Whether you’re building a fire indoors or outdoors, you can expect it some popping and crackling. It’s a common phenomenon that occurs when burning wood. Excessive popping and crackling, however, is a sign of low combustion efficiency. And if left unaddressed, the excessive popping and crackling could project fiery-hot embers that cause bodily injury or property damage.

Understanding the Combustion Process

When burned, firewood undergoes a chemical reaction known as combustion, during which the wood matter is converted into heat. More specifically, the cellulose within the wood reacts to the oxygen to produce heat. When a fire has a poor combustion process, meaning only a minimal amount of matter is converted into heat, it will release more airborne particulate matter. Some of this particulate matter will manifest as thick black smoke, whereas others will manifest as embers that pop and crackle.

How Moisture Causes Fires to Pop and Crackle

In addition to low combustion efficiency, trapped moisture can cause fires to pop and crackle. Even if a piece of firewood looks dry, it probably has moisture inside its pores. After all, trees absorb water to grow and survive. Without water, they wouldn’t be able to transfer nutrients, nor would they be able to produce energy via photosynthesis. Heavily saturated firewood, contains a substantial amount of moisture — so much, in fact, that it restricts the combustion process. And as previously mentioned, inefficient combustion can cause wood to pop and crackle when burned.

Trapped moisture can also cause wood to pop and crackle from the creation of steam. Unlike wood, water doesn’t convert into heat when burned. If you place a pot of water on the stove and activate the burner, it will evaporate as steam. This same principle rings true when burning wet or moist firewood. As the trapped moisture heats up, it will turn to steam. Unfortunately, this often results in the creation of steam pockets inside the wood. The steam remains trapped inside these pockets, and as the pressure increases, they may burst to create popping and crackling.

Use Kiln Dried Firewood

To minimize popping and crackling, use kiln dried firewood to build your fires. As the name suggests, kiln dried firewood is processed in a heated kiln. Some kilns are powered by electricity, whereas others are powered by steam or even solar energy. Regardless, they all expose wood to heat, which works to release the trapped moisture and create exceptionally dry firewood.

When processed inside a heated kiln, wood becomes drier. Even if the wood initially had a 100% moisture content, kiln drying may lower its moisture content to just 10% to 15%. Of course, that’s substantially drier than air-dried firewood, which usually has a moisture content of about 20% to 25%. And if you purchase kiln dried firewood from Cutting Edge Firewood, you can rest assured knowing that it’s been processed for 12 times longer than the United States Department of Agriculture’s (USDA) standard for kiln drying. As a result, it burns cleaner to produce more heat with less popping and crackling.

Stick With Hardwood Varieties of Firewood

Hardwood varieties of firewood are less likely to pop and crackle than softwood varieties. There are a few reasons for this, one of which is the low moisture content of hardwood. Most hardwood varieties have a lower moisture content than softwood varieties, so they typically don’t produce steam pockets when burned.

Furthermore, hardwood varieties of firewood contain less resin and tar than softwood varieties. Resin and tar is particularly problematic because of its ability to seal specific sections inside the wood. As these organic substances heat up, they expand to fill cracks and crevasses. If there’s any moisture trapped behind this newly formed seal, the intense pressure may cause it to burst. Hardwood varieties of firewood, however, contain less resin and tar than softwood varieties, so they are less likely to pop and crackle.

Store Your Firewood in a Dry Area

Whether you use oak, hickory, cherry or any other hardwood variety of firewood, you should store it in a dry area. Just because your firewood is currently dry doesn’t necessarily mean that it will stay dry. Storing your firewood outdoors without any form of coverage, for example, will likely result in it getting wet. Even if it doesn’t rain, your firewood will still be exposed to humidity. Over time, constant exposure to humidity will saturate your firewood with moisture, which may lead to it popping and crackling when burned.

Follow these tips when storing your firewood to keep it dry:

  • Make sure your firewood is covered if you’re planning to store it outdoors. You can use an awning, roof or even a tarp to cover your firewood.
  • In addition to being covered, firewood should also be stored off the ground when outdoors. When firewood is placed directly on the ground, it will absorb moisture. Therefore, you should keep it at least 2 inches off the ground.
  • Consider storing your firewood somewhere inside your home, such as near your living room fireplace. A basic metal rack will allow you to easily store your firewood near your fireplace where you can easily access it.
  • Avoid storing firewood in humid areas of your home like a crawlspace.

Build Bigger Fires

The size of your fires can affect whether or not they pop and crackle. Generally speaking, bigger fires are less likely to pop and crackle than smaller fires. If you build a fire with only two or three small logs, it probably won’t produce much heat. The low temperatures restrict the combustion process, resulting in less heat. At the same time, the firewood will release more particulate matter into the air, some of which may cause popping and crackling.

By building bigger fires, you can avoid these problems. Don’t just toss a couple small logs into your fireplace, fire pit or other wood-burning accessory. Instead, use more — as well as bigger pieces — of firewood.

Open the Damper All the Way

When building fires in a traditional wood-burning fireplace, make sure the damper is open all the way. All fireplaces have a damper. It’s typically found inside the flue directly above the firebox. The purpose of the damper is to control airflow into and out of the firebox. If the damper is closed, air won’t be able to enter through the chimney. And since wood needs fresh oxygen to burn, this will cause the temperature to drop.

If you’re planning to a build fire in your fireplace, you need to open the damper all the way. Even if it’s just partially closed, it will still restrict the amount of fresh air that enters the firebox. More importantly, a partially or fully closed damper will contribute to creosote buildup. Smoke won’t be able to escape the firebox if the damper is closed. As the smoke accumulates inside the chimney, it will form creosote inside the walls. Not only does this lower the performance of your fireplace; it creates a serious safety hazard. Creosote is highly flammable and may ignite from just a single stray ember.

Stock up on premium kiln dried firewood by visiting our online store today. We offer a variety of kiln dried firewood, including oak, hickory and more, that will help you build cleaner fires with less popping and crackling.