Firewood is often classified as either seasoned or unseasoned, depending on its moisture content. There are over 60,000 species of trees. Regardless of the species, though, all types of firewood can be classified as seasoned or unseasoned. If you’re looking to build brighter, hotter, longer-lasting fires, you should familiarize yourself with the differences between seasoned and unseasoned firewood. Only then can you choose the right firewood for your fire-building needs.

What Is Unseasoned Firewood?

Also known as fresh firewood, unseasoned firewood is characterized by a high moisture content. It’s either not dried after being harvested from a tree, or it’s improperly dried after being harvested from a tree. All living organisms need water to survive, and trees are no exception. From pines and oaks to maples and hickories, all trees use water to facilitate in the conversion of sunlight into energy. As a result, newly harvested firewood contains moisture, which is measured in its moisture content.

The moisture content of firewood refers to the percentage of its water weight relative to its dry weight. What’s a normal moisture content for unseasoned firewood? It varies depending on the species, climate and other factors. According to the University of Tennessee (UT), however, most types of unseasoned firewood have a moisture content of 60% to 120%. Unseasoned oak firewood, for instance, has an average moisture content of 75%, meaning it contains three-fourths its total weight in water.

What Is Seasoned Firewood?

Seasoned firewood, as you may have guessed, has a low moisture content. Like unseasoned firewood, it’s harvested from a tree. The difference is that seasoned firewood undergoes an additional step before it’s sold and used as fuel. After the tree has been cut down and processed into logs — which are usually split using an ax and log splitter — the firewood undergoes a drying process to lower its moisture content.

There are several different methods used to dry firewood and, therefore, make it seasoned. The most common method is air drying, which lives up to its namesake by using air to lower the moisture content of firewood. The firewood is stacked outdoors where it’s stored for at least six months. Over the course of this period, moisture will evaporate from the firewood. After the firewood has air dried for an ample length of time, it’s sold and used as fuel.

Another drying technique used to produce seasoned firewood is kiln drying. Kiln drying is a more methodical and advanced method that, when performed correctly, offers an even lower moisture content than air drying. It involves baking firewood in a large oven-like device known as a kiln. Once inside the kiln, the firewood quickly dries out. Water doesn’t just evaporate from the wood. Rather, it’s forced out using heat and pressure. As a result, kiln drying is significantly faster than air drying. More importantly, though, it’s able to extract more moisture from firewood than air drying.

While unseasoned firewood has an average moisture content of 60% to 120%, seasoned firewood contains substantially less moisture. When air dried, firewood typically has a moisture content of 20% to 30%. When kiln dried, firewood has a moisture content of 10% to 15%.

How to Tell Whether Firewood Is Seasoned or Unseasoned

While you can’t easily measure the moisture content of firewood, there are other ways to tell whether it’s seasoned or unseasoned. For starters, seasoned firewood weighs noticeably less than its unseasoned counterpart.  As previously mentioned, unseasoned firewood can contain over twice its weight in water, whereas kiln dried firewood often contains just one-tenth its weight in water. When holding an unseasoned log in one hand and a seasoned log in the other hand, you should notice the difference in weight.

In addition to weighing less, seasoned firewood has a lighter and more faded color than unseasoned firewood. Moisture is partly responsible for the color of firewood. The more moisture a piece of firewood contains, the darker its color will be. Fresh, unseasoned firewood typically has a darker tone, whereas seasoned firewood has a lighter tone.

You can also look for cracks in firewood to determine whether it’s seasoned or unseasoned. As firewood dries out, it develops cracks due to contraction. Loss of moisture causes the firewood to contract and, in turn, develop cracks. Of course, you’ll probably discover cracks in both seasoned and unseasoned firewood. Normally, though, seasoned firewood contains more cracks than unseasoned firewood.

Why You Should Only Burn Seasoned Firewood

Don’t make the mistake of burning unseasoned firewood. With its high moisture content, it’s a poor choice of fuel for a variety of reasons. All the moisture trapped inside unseasoned firewood makes it difficult to light. You can go through an entire book of matches trying to light unseasoned firewood, all to no avail.

Even if you’re able to light unseasoned firewood, it won’t burn cleanly. What does this mean exactly? Unseasoned firewood has a high moisture content, which among other things, interferes with its combustion process. Combustion is a chemical reaction in which wood is converted into heat with the help of oxygen. Moisture inhibits the combustion process of firewood, resulting in less wood being converted into heat. Instead, a substantial amount of the wood is simply released in the form of particulate matter.

Seasoned firewood produces a fragrant and pleasing aroma that’s not found in unseasoned firewood. You’ll encounter different aromas depending on the particular species of firewood you burn. Nonetheless, all types of well-seasoned, high-quality firewood produce a fragrant aroma that fills the surrounding space. Whether you build a fire indoors or outdoors, seasoned firewood will create a pleasant aroma.

You don’t have to worry about bugs or pets with seasoned firewood. Assuming it’s well-seasoned, such as kiln dried firewood, it will offer a naturally high level of protection against bugs and pests. Insects typically prefer to feast on unseasoned firewood. Seasoned firewood contains a minimal amount of moisture, so it’s not an ideal source of food for wood-devouring bugs and pests. This is just one more reason why you should choose seasoned firewood.

Choosing seasoned firewood is particularly important when building fires inside your home. If you have a wood-burning fireplace or stove, you shouldn’t use unseasoned firewood. We’ve already talked about how unseasoned firewood produces soot-filled smoke when burned. Well, if you burn it inside your home, all that soot-filled smoke will fill your fireplace’s flue or your stove’s ventilation pipe. Over time, some of the particulate matter in the smoke will accumulate inside the flue or ventilation. As the clogged flue or ventilation restricts airflow, toxic gases like carbon monoxide can accumulate inside your home. You can avoid such problems by choosing seasoned firewood rather than unseasoned firewood.

In Conclusion

To recap, the difference between unseasoned and seasoned firewood lies in whether they are dried during production. Unseasoned firewood is not dried during production, resulting in a higher moisture content. Seasoned firewood, on the other hand, is dried during production, resulting in a lower moisture content.

Experience the difference kiln dried firewood makes in your fires by visiting our online store today. Cutting Edge Firewood is the Southeast’s premier vendor of high-quality kiln-dried firewood. We offer a variety of the industry’s finest firewood, including oak, hickory, cherry and more.