flame temperature of various woods?

I can find heat content (Btu/lb) of various hard and soft woods from various sources. However, I have heard that some woods, such as cedar, which is available in abundance here in Missouri, burns hotter than other wood, even though it doesn't have as much heat content as hardwoods, such as hickory, oak, locust, or osage orange. Can someone please provide a table of flame temperature of various woods? In searching on google, if you look for words "combustion temperature" it is sometimes confused with "ignition temperature" which is not what I am looking for.

Some old timers here claim that cedar burns the hottest of all because of its sticky sap content. Any comments on cedar or flame temperature would be appreciated.

Yes, there are maple syrupmakers in Missouri, mostly in the hill country of tributaries of the Missouri and Mississippi rivers, and in the eastern half of the state. I have met about a dozen of them, and some of us are already boiling! We had a 15" snowstorm in mid Missouri a week ago and the subsequent days, though foggy and cold, led to some good sap flow. We now have an arctic air mass, so the trees are sleeping for a while.

Good luck to readers in New England who are getting a snow blast tonight. Your sap will flow in a few weeks! John

That’s an interesting question. I would guess that while it may be true that some types of wood burn hotter than others, the differences would be negligible, especially when compared to other factors such as cost, availability, and moisture content. In other words, burn what you have on hand and make sure it’s dry.

If I remember right all wood has the same btu's per pound. Pine pitch can add some btu's. The temp depends on getting the fuel to air ratio correct and less moisture to interfere with mixing.

https://www.environmentalchimneyserv...burns-hottest/

This may be more what you are looking for:
http://worldforestindustries.com/for...d-btu-ratings/

Unless you are just curious, don't worry about it's flame temperature. Just give it all the oxygen it needs and keep adding wood according to a timer. I've burned everything from Bass wood, to oak, cedar, cherry, locust, ash, sugar maple, pine and hemlock plus many others. While each species may need a longer or shorter refuelling interval, they all boiled just as well as any others, you just need to figure out the time for adding more. On mine, once I added AOF (air over fire) has been 8 minutes on the softer woods to 9 if all harder woods. Just make sure it's dry and split to wrist size in at least 1 dimension and not over 2x wrist size in the other.

I came across a bunch of cedar in the wood I had put up for last year's boil. I decided I like using it.

Burns a little quicker and so I had to adjust stoking time.

It doesn't leave as much hot coals so shutting down for the day is easier to control.

Plus I'ld rather use the hardwoods for the wood stove.

This year I believe I have enough cedar in the shed for the maple season.

If you find it, it would be incorrect to take that as your operating temperature..
the fire temperature can get hotter for any wood if there is good oxygen and insulation in the burn chamber. It gets lower as a result of moisture. So regardless of type, if it is very dry, and plenty of oxygen, it can burn hot. Cardboard for example can burn very hot since it is typically dry and the corrugations trap air. Splitting smaller kindling size of any type will allow a faster burn, making more heat in a period of time, and thus being hotter. So a given type of wood or any other fuel can have a wide range of operating temperature. Oak is know for good btu value, but that is really based on cord, or volume purchase. If you get dry wood, they are all similar btu per lb dry. Since often is available green, the ratings are easily comparable by volume. In your arch, the lighter wood may actually burn faster, and hotter, if it is dry, than hardwood.
Hope this helps.

I've boiled with several types of very dry punky wood in the past and have had trouble keeping sap in the pans without using a lot of defoamer ( especially dry punky hard maple). I like boiling with lighter weight wood of all types as long as its dry. I am still boiling with cottonwood that has been in the woodshed for 6 years now. Have several more years worth in there.

I agree with some comments that BTUs seem generally related to dry density. And, more moisture means more BTU to extract the water. Also, I don't think the burn temperature matters but the burn time does. Lighter wood generally means less BTUs and a shorter burn time. More moisture means more BTUs towards drying.

Qualifier: I'm not just a Rookie, I'm a Rookie 1st Class!

And if you're in a pinch, like I usually am, standing dead elm that has shed its bark (but still solid) is what I go for if I can find it. Turns the arch doors cherry red.

For the smaller operators and backyarders pound for pound the fastest hottest burning wood is old pallets. Usually available free. Some work to cut up but they really add the heat....
An option for those limited on fuel supply

From Chapter 7 of the 2006 edition of the North American Maple Producers Manual.

Attachment 19569

A lot burn whatever they can get. Hemlock burns hot but quick, more times stoking, more coals.
Find a tree service company, ask about they do with what they take down.
I used one that took down some with their cherry picker and standing dead. They left 3’ x8’ stalks, cut stand dead hemlock and took to a farm store that they use for outdoor furnaces and chipped up branches and rotting 2’+. I had to pay the crew.
Then 2 other times they cut down and grown stumps, I processed wood for sugar (hemlock,maple, beech, birch and hardback).

i used to use the same wood in the arch as i did in the camp stove but as red said, i now prefer to keep the maple and ironwood for heating my home and camp. i look for any punky wood that's in the woods. i have a lot of basswoods that come down in storms. popple n spruce burn hot. you get a lot less coals to choke the draft and i'm not concerned about firing up more often. i'm watching water boil; it's good to have something else to do!

I typically burn oak and locust but when I am getting close to syrup, I like a hotter flame so I will burn red maple or poplar. I believe that it gets the syrup to migrate better. I may be wrong but in my experience, I have watched sap bounce 2 - 3 degrees below syrup for a long time before becoming dense enough but when I make the fire hotter with softer woods, the sap gets to syrup quicker.

In short, I agree that some wood burns hotter but gives less btu's. But those hotter burning woods usually burn faster.

I burn red maple black cherry red oak These are just blow downs around the woods around the house.I saw on Dr. Tims sheet ash is good,there is a little poem that oak is dense and burns well but ash shall heat the hearths of kings.

I burn a lot of ash (mixed with box elder, elm, maple, etc). Definitely gives off its BTUs faster than a lot of other woods but still not too frequent firings. Makes the evap boil really well and it's a noticeable difference compared to say armloads of box elder or oak. Elm is a close second in my favorites to use. Firing with both elm and ash makes serious heat.

Something else that I have found is that the softer hardwoods seem to burn at a more even temperature. With locust and oak, my temperature readout is constantly fluctuating around 1/2 a degree but red maple and cherry seem to only fluctuate about 1/10 a degree. Drawoff is much more steady with the softer woods.

The Firewood Poem
Beechwood fires are bright and clear
If the logs are kept a year,
Chestnut's only good they say,
If for logs 'tis laid away.
Make a fire of Elder tree,
Death within your house will be;
But ash new or ash old,
Is fit for a queen with crown of gold

Birch and fir logs burn too fast
Blaze up bright and do not last,
it is by the Irish said
Hawthorn bakes the sweetest bread.
Elm wood burns like churchyard mould,
E'en the very flames are cold
But ash green or ash brown
Is fit for a queen with golden crown

Poplar gives a bitter smoke,
Fills your eyes and makes you choke,
Apple wood will scent your room
Pear wood smells like flowers in bloom
Oaken logs, if dry and old
keep away the winter's cold
But ash wet or ash dry
a king shall warm his slippers by.

Fuel+Temperature+Oxygen=Fire There are an infinite number of permutations in this formula that result in getting firewood to boil sap, but a lot of the heat still goes up the stack unused. Terrible efficiency.

Quote:

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Originally Posted by Daveg

Fuel+Temperature+Oxygen=Fire There are an infinite number of permutations in this formula that result in getting firewood to boil sap, but a lot of the heat still goes up the stack unused. Terrible efficiency.

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Maybe inefficient, but still cheaper (by 50%) to heat my house with wood instead of LP. And all I do is buy it - cut, split, deliverd, and stacked (2 years ahead) move it to the house and burn it.