Let’s Compare Wood Drying Methods: Kiln-Dried Wood vs. Seasoned vs. Pressure-Treated!
When shopping for cooking wood, you’ll see different terms for wood drying methods. Terms like “kiln-dried,” “seasoned” and “pressure treated” describe wood drying techniques. And each method affects how good the wood is for cooking.
But what do these terms mean? And does it matter how the wood is dried?
In this blog, we will define each of these terms for you and explain whether they’re good for cooking. But before we discuss that, we need to discuss wood moisture content and why wood is dried in the first place.
What is Wood Moisture Content?
Wood moisture content is the percentage of mass relationship between the mass of wood without water and the mass of wood with water. For example, if a piece of wood weighs 100 pounds, and contains 50 pounds of water, then it has a moisture content of 100%.
As we will see, drying cooking wood is essential because the high moisture content is detrimental to how the wood performs. We can see this most clearly in the ultra-moist example of green wood.
What is Green Wood?
Green wood is freshly felled wood that has not gone through any kind of drying process. When you cut down a tree and split it into firewood, the resulting pieces are green wood.
Important Facts About Green Wood
The moisture content of green wood ranges from 60% to 200%, depending on the kind of wood and the outdoor conditions. With a moisture content this high, it is practically impossible to cook with green wood. The wood is difficult to ignite and burns with a lot of dark smoke. If you try cooking with green wood, you probably won’t get your oven hot enough. Even if you do, it will be full of smoke that will leave a bad flavor on your food.
Furthermore, green wood often contains mold, insects or fungus because it lacks proper heat treatment. Like any food ingredient, wood is best when it doesn’t contain bugs or mold.
The Verdict on Cooking with Green Wood
For all these reasons and more, we do not recommend cooking with green wood.
What is Kiln-Dried Wood?
Kiln-dried wood, also called heat-treated wood, is wood that has been heated at 200+ degrees for between 24 and 72 hours, depending on the size of the wood.
The moisture content of kiln-dried wood is usually between 6% and 9%, depending on the length of drying time. The longer kiln-dried wood is left in the kiln, the drier it becomes.
Important Facts About Kiln-Dried Wood
Kiln-dried wood has a few distinct benefits over other forms of drying. First, it is a reliable method of drying because weather conditions don’t affect it. If rain soaks the wood, the kiln will still dry it quickly and effectively.
Second, kiln-drying kills bugs, fungus, and mold every time, without fail. No bugs, mold, or fungus can survive the extended high temps in the kilns, meaning it’s perfect for cooking wood.
Finally, kiln-dried wood ignites easier and burns cleaner and hotter than wood from other wood drying methods. The low moisture content makes the wood simple to ignite and means it will burn with very little smoke once lit. Additionally, the low moisture content of kiln-dried wood allows it to reach significantly higher temperatures, making it the perfect solution for wood-fired pizza ovens.
The Verdict on Cooking with Kiln-Dried Wood
Ultimately, kiln-dried wood is the best wood for pizza ovens and for cooking in general.
What is Seasoned Wood?
Seasoning is a method of drying wood outside for roughly one season. After being felled, wood can be stacked and left outdoors to reduce its moisture content.
Important Facts About Seasoned Wood
The moisture content of seasoned wood can vary between 20% and 30%. Even the best seasoned wood is very unlikely to reach a moisture content below 20%. Furthermore, seasoning is an unreliable method of drying for a few reasons.
First, weather conditions affect how quickly wood can dry from seasoning. In hot, dry summer months, wood will dry faster and reach a lower moisture content from seasoning. However, in wet spring, fall, and winter months, firewood will barely dry.
Second, seasoning wood requires a special stacking method that allows air to travel between the pieces effectively. If it isn’t properly stacked with space between pieces, it will dry very slowly, no matter the weather conditions.
The Verdict on Cooking with Seasoned Wood
With all the above in mind, the results from seasoning wood are highly variable. Can you cook with seasoned wood? Yes, sometimes you can. However, it has to be properly stacked and left out to dry in ideal weather conditions for a long enough time. Because of this, we can’t guarantee that seasoned wood will be dry enough for cooking.
On top of that, seasoned wood that is not dry enough can still contain bugs, mold or fungus. It is for this reason that we say “it depends” when asked whether seasoned wood works for cooking.
What is Pressure-Treated Wood?
Pressure-treated wood is wood that has been put under high pressure to force a chemical solution of preservative agents deep into the wood. This process makes the wood last longer in harsh weather conditions and is typically used for construction projects.
Important Facts About Pressure-Treated Wood
There are several chemicals that can be used to pressure treat wood. All of them are dangerous to burn.
One of those chemicals, copper arsenate, releases arsenic into the air when burned. Arsenic can cause acute and long-term poisoning and is always toxic to humans. You should never breathe in arsenic or allow it on your food or in your oven.
The Verdict on Cooking with Pressure-Treated Wood
Never cook with pressure-treated wood. The moisture content is irrelevant because it is dangerous to burn, dangerous to cook with and dangerous to allow to build up in your oven.
Want Some Dry Cooking Wood of Your Own?
We hope this article has helped you understand the differences between these wood drying methods.
The bottom line is that kiln-dried wood is the best option for cooking. Green wood is far too moist to cook with, and you should never burn pressure-treated wood because it is dangerous. And while you may be able to use seasoned wood, it comes with far too many variables compared to the proven performance of kiln-dried wood.
For all of these reasons, we at Hot Box Cooking Wood only use kiln-drying to produce our six-inch wood for portable pizza ovens. If you want to learn more about our product, feel free to visit our product page or follow us on Instagram @hotboxcookingwood.