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Seasoned Firewood vs. Kiln-Dried Firewood  

Dry Seasoned Firewood

Seasoned FirewoodSeasoned firewood with bark that is tight to the wood so you can tell it is not kiln-dried. Click on the image for a larger view.

Historically, wood has been burned here in Massachusetts by a primitive man who burned wood to eat and heat. Today's man wants a romantic fire to relax by. In all cases, anyone trying to light a fire would look for dry wood since, after one or two fires, everybody knows that drier is better. Pretty soon, you get firewood connoisseurs who appreciate a good "firewood concierge"! For them, it is to get good wood that burns right and is easy to light.

The question about moisture is pivotal in getting good wood that will burn well. The term seasoned wood can be applied to firewood that is excellent for burning in the fireplace and a firewood product that can be like burning a wet sponge. A new term called "Semi-seasoned" has been coined in the firewood industry. This is because many firewood suppliers cannot keep up with firewood's "seasonal" nature they sell that wood out too fast. With a surge in firewood requests over the winter, dealers offer wood that is not ready to be burned and has not been cut and split for four-plus seasons as it should be to dry out to a low moisture content naturally. So, in this industry, there is a huge gray area regarding what it means when people refer to seasoned wood. It is important to be aware of these variations as a consumer. We have a page showing a side-by-side comparison of seasoned firewood to kiln-dried firewood.

Caveat Emptor

Please be aware this page is authored by a Firewood supplier that has consciously decided only to sell kiln-dried firewood and no other firewood product. The concern is we want to be a brand that is known as having good wood that lights well, smells great, burns bright, and the customer knows what to expect each time they buy our product. This focus does not mean we do not know what is going on in the industry and the science of drying and burning firewood. We travel to New England, New York, and Pennsylvania and visit other firewood suppliers. One key observation is to go by other suppliers' yards that sell "Seasoned Firewood." Almost 100% of them are sold out and empty from April to May and start to fill up by June. One supplier's yard fills in June and is empty at the end of October, so by definition, it can not be well-dried. We know of one supplier that has wood from the previous year and dried it to sell next fall. We suggest you, the reader and buyer of firewood, should do the same. Take a look at their locations in spring, late summer, and fall. This is our industry experience; see for yourself. There are a number of economic factors that play into this.

Indicators of Firewood Moisture

smoldering firewoodGreen-Wood Smoldering Who Wants This in There HouseIf, you have trouble starting your fire or have trouble keeping your fire going, you are probably using recently-cut green wood, meaning that it is neither kiln-dried nor seasoned. If firewood is not properly dried, it will be hard to light. The moisture content of freshly-cut wood can be in the range of 70 percent in oak, and Sycamore has been tested to be all the way up to 114 percent. Kiln-dried wood is in the range of 20 percent moisture. Quantifying it like this, you can imagine how unseasoned wood will keep going out. It will smolder; it won't put out heat; it just burns poorly and inefficiently. The heat of the fire is taken up by drying out the water in the wood. The species of wood also affects how it burns. Trees that are classified as hardwoods are very dense, and they have more BTUs (= heat) per volume than softwoods. They tend to be more difficult to start but will burn longer and release a lot of heat, and if the moisture content of these hardwoods is low, the difficulty in starting the fire goes away. For all practical purposes, kiln-dried hardwoods are the best choice for firewood.

How Seasoned Firewood is Made

The concept is very simple: cut the wood to length, split the wood, stack the wood, give it air circulation, and protect it from rain, snow, and fog so the wood will dry out over time. It is not rocket science that is a good old catchphrase. The science is creating a moisture gradient that is lower outside of the wood so that the moisture, over time, is pulled out of the wood. It is a simple concept but everybody has an opinion on what is the best way to go about handling wood so that it will be a "good" seasoned wood. By "good" seasoned wood, we mean a wood that, when ready it is put in the fireplace it lights and burns well and then burns completely to the end of the fire. The opinions on how to stack the wood and the patterns people use for seasoning wood are fascinating. Big piles that are piled high with no air able to circulate can create a mold to build upon the wood. Stacked wood with the sun on the face of the stack helps prevent molding but some kind of loose cover on top helps to shed water on the pile away from it as it is drying.  Stacked firewood can be a real work of art to look at that would make a great portfolio of pictures. 

Why it is Hard to Get Good Seasoned Firewood

It is a Question of Time and Space

No time machine can transport firewood back from the future, and no rocket ship can haul firewood to break the time continuum. We mean that the time to produce high-quality firewood is just plain long. Specifically, it is 12 to 18 months in low humidity conditions. The same as wood can be dried out it also will absorb moisture back into the wood if in high humidity. There is no way to speed up the process other than by adding heat with kiln drying. To put it another way, in Banking, there is truth in lending, but in firewood, there is no regulation in truth in drying. That's why there is so much discussion about it.

season wood pile smallAcres of Seasoned Firewood Piled Up In The Spring Because it takes so much time to dry, the space needed to dry firewood is large. The total dollars and profit potential are not really large to afford space that only generates revenue for a 3 to 4-month period. The equation does not work. The labor is high and the space needed is large. Urban firewood is just hard to do. I would be so different around Lee Ma with space and room.

Here is the next collision with facts. Boston real estate is expensive and going up every day a new corporation moves to the area. So Space Firewood is bulky, especially when you start to consider the volumes of wood needed to supply firewood users in Boston and its suburbs. It is just too darn expensive to have firewood stored in a ground-level lot that would take at least an acre of space in any place close to Boston with the size needed.

Trucking to overcome the space issue is a natural way to overcome the need for space by bringing it in from other places. Simple to say but the cost of loading and handling any bulk material is expensive every time you handle it. Then the cost and availability of trucks are getting all out of whack.

Kiln Drying Firewood Overcomes the Need for Time

Borrowing from technology to dry lumber for building purposes, companies have now set up kilns to dry firewood. Wood from forestry projects that would have gotten ground up or used some other way does not go to make firewood. A tree can be cut down, and in less than 7 days, that same piece of wood can be at 12% moisture content that burns better than seasoned wood. Well-dried seasoned wood can get down to 20 to 30% moisture, and customers who have tried both will not accept firewood with 25% moisture content as good burning firewood.

How to tell if your firewood is dry

Seasoned and kiln-dried firewood is dark or gray compared to freshly cut green wood. To test the difference, split a piece of seasoned wood. You will see that it is a white color inside. The wood splinters are less flexible or brittle than fresh-cut firewood since the moisture content is reduced. The wood will have cracks running through each piece and a lot of little cracks on the inner rings. These cracks are caused by the drying, creating shrinkage in the wood itself. Unseasoned wood has a wet, fresh-looking center and is lighter than the dried wood near the edges or ends exposed since cutting. Comparing the same wood species will make the differences between dry wood and green wood very clear. Another fast way to spot if firewood is very fresh is the bark will be very tightly attached. With drying, the two different layers pull apart.

Since water in the wood prevents the wood from burning, it also adds weight to the wood. After picking up a lot of wood, you get used to the "Feel" of dry wood. We know it from experience, but the average person cannot tell. The difference in one piece of wood the same size can be one-third less. Some people have put the wood in the oven to heat it up and measure the weight of the wood before and after it is dried. The difference is wood weight. 

One of the other ways to check a load of wood after it is delivered is to pick up two pieces of wood that are the same size, bang them together, and listen to the sound it makes. If the wood clapped together makes a dull thud, then the wood is wet. The water in the wood muffles the sound from resonating in the wood. Doing the same thing with two pieces of well-dried firewood, you will get a sharp cracking sound like a wood baseball bat hitting a home run. If you are unfamiliar with the sound, we have a video where you can hear what it sounds like when pieces of dry wood are hit together.

Testing Firewood For Moisture Content

There are ways to test if the firewood is dry. Some of it is covered above by looking for the right things. Some battery-operated testers give a digital readout after you put the prongs in the wood. For a homeowner, this does not make a lot of sense. Buy from a reputable company that handles quality wood. A very accurate test is to take two pieces of wood and bang them together. The sound it makes tells you if the wood is dry. A wood with a high moisture content will produce a dull thud. Dry wood knocked together will have more of a ring to it. The concept is simple but very effective.


Firewood with a high moisture content has been proven to cause creosote to build up at an accelerated rate in the chimney. So, buying less expensive wood will make it heavier to carry and handle, burn poorly, and cause chimney fires if not cleaned often. One fresh-cut cord of oak may contain enough water to nearly fill six 55-gallon drums. The water content in the wood determines how much heat the fire puts out and how much creosote will build up in your chimney.

Avoid these hassles at all costs! When you get cold, you'll be miserable if your firewood does not produce the heat you need. Well-seasoned, kiln-dried firewood produces pleasant, trouble-free heat. We both take the water out of the wood and the hassle out of getting the amount you want to be placed right where you want it when you want it.

Call The Firewood Concierge at 781-254-2773 to get your wood today.