LOL, So hot it created ash!
No I think the highest it gets it around 160 degrees American(F)
I've seen it happen plenty, it's a symtom of a pile being too dry the microorganisism or fungus or whatever created a dust like substance.
It's best to not breath this, and wear at least a bandana when working in a dry pile. And water it down too.

LOL, So hot it created ash!

At first I was a little miffed by this response, then once I thought about it I realized it was a bit silly. (blush)

It's late is my best excuse - that and the fact that I could have sworn I read something about this before. Must be a senior moment.

The pile is made up mostly of broken up sod and some left over leaves and I did water it down pretty good as I built it. It still seemed slightly damp when I turned it but I added more water anyway. I'm pretty new to the whole composting thing so I'm still learning. I was surprised to read the fungus/ash might actually be harmful. Still learning! Thanks.

Val

Compost can get hot enough to spontaneously combust, but it usually only happens with really big piles. A similar question was here recently, and somebody did report having a backyard compost pile catch fire.

It's possible that you're seeing ash, but it's more likely some kind of fungus.

You probably did read that it could be ash. There have been a couple of threads recently discussing spontaneous combustion in compost. I couldn't find them with the search function, but I knew they were recent. There was also a thread a year or two ago with pictures of a compost fire at a commercial facility, but I couldn't find that.

Here is one thread on the subject.

Here is another, with a link to yet another thread.

My bad, I jumped the gun making fun of you *lillies*
Well, if it's true a compost pile can spontaneously compost, it's got to be true humans can too right? LOL. Where's the proof? I bet if it's dry enough, but aren't you supposed to keep it moist.
Thus a "compost spontanenous combustion" is just an abandoned pile? Ok I won't nit pick anymore *grins*

I think this is not a bad sign, what you experience with this dust. And depending on cicumstance it could be spontaneous combustion. Can you give us more details about the amount of material noted?

Ooopps, jumped the gun again.

Sounds like a common case of dryness within the pile. I've experienced this too, where you think you water enough, but if you pitchfork the pile 6 inches deep, it's still dry, and even after multiple waterings there can still be dry spots.

Especially in areas of drought, dry compost piles are a huge problem, thus people are utilizing rain barrels and gray water.

Check out these posts I dug up on the subject!

· Posted by ericwi Dane County WI (My Page) on
Wed, Aug 9, 06 at 21:56
If you build a really big pile, with just the right ingredients, it can catch fire, and smolder. Last year there was a thread about a cattle rancher out in Idaho, who piled up a small mountain of manure mixed with bedding. The pile caught on fire, and he was not too popular with the neighbors. Something about the smell.

· Posted by adirondackgardener z4a Adks. (My Page) on
Wed, Aug 9, 06 at 22:16
There are always reports of compost piles catching fire. They invariably are very large piles, usually in industrial settings. I've never read of reports of home-sized compost piles spontaneously combust. Is it possible? Yes, of course. It's possible your compost pile could also be struck by lightening. Will you be trucking in composting material in tandem trucks? If so be concerned. I have no thoughts about your left-over pancakes. Wayne

· Posted by lee53011 5 (My Page) on
Wed, Aug 9, 06 at 22:17
You would have to be doing commercial composting, like dump truck loads, to worry about spontaneous combustion. Even then you wood have to have the perfect mix to get the right gases or whatever for it to ignite. Remember that compost should be kept about as moist as a wrung out sponge. If you can get the compost to around 150 degrees it will kill any weed seeds in the compost. That is a good temperature. Yes you can compost pancakes. I usually digest them instead!! Lee

· Posted by carolinakate 7b (My Page) on
Wed, Aug 9, 06 at 22:35
If the temperature gets above 158 degrees, many of the microbes will start dying, and the process will slow down. I don't know how likely it is that a home composting system will ever reach these temperatures, but to keep it actively composting, try to stay between 110 and 150. Keeping it above 131 for 14 days will kill the weed seeds. K.

If what you have looks like some ash from a fire and the material is still fairly intact, ie. a maple leaf that is ashey and still looks like a maple leaf, you most likely had what is known as "flash" something that happens in a compost pile, most often where the material to be digested is exposed to heat but is too dry to be digested.
There are still skeptics around but compost piles, like any other organic matter, can and do spontaneously combust. Any one that does not believe a compost pile will probably does not believe that linseed oil soaked cotton rags will either. If the proper conditions are present any type of organic matter will spontaneoulsy combust.

bpgreen - Thanks for finding that second link! I KNEW I'd read something about it before but for the life of me I couldn't find it in a search.

That post read almost exactly like what I experienced. This is the first time I'd ever seen this ashy stuff so I was surprised. Also tho, it's the first time I'd ever had a huge amount of grass to put in so I just wasn't sure what was going on.

Does anyone think the grass has something to do with the ashy stuff showing up?

what is known as "flash"

Ahhh....this is a new term I hadn't heard of. Thanks. What you describe is exactly what I had. The broken up sod was still basically intact but had an ashy substance on it. Looks like the consensuses is more water is needed.

Val

hi val, Ive found the same stuff in my compost, and yes it really does look like ash so dont feel silly. I only find it when I add a lot of grass clippings and the area I find it in is dry while the rest of the compost is still moist. Im not sure either way what causes it but it doesnt seem to cause any ill effects.

I only find it when I add a lot of grass clippings

Thanks, Trance. I wondered if the grass had something to do with it. It's also nice to know about not causing ill effects...I was starting to picture biohazard suits :-)

Val

Hi Val

Yup, had it, didn't know what it was either. Seemed to disappear when mixed so I didn't worry about it.

Also, first I've heard of Fahrenheit being referred to as "American" as in "160 degrees American(F)". Is this a common reference in the land of the free?

Lloyd

I'm going to try mixing and watering again this weekend so it'll be interesting to see if it's still there or if it's disappeared. Thanks, Lloyd...it's actually kind of good to see so many other people have seen it as well.

I too thought it was a little different the way the temperature was listed but was more wondering why we (maybe me) was referred to as "lillies".

I jumped the gun making fun of you *lillies*

I'm hoping that is his favorite flower :-)

Val

Generally, "flash" is not very bad and is mostly a momentary occurance. But it does tell you that conditions did exist, even if only momentarily, for spontaneous combustion, something you do not want to happen.

I don't believe that most of these are "flash". I think that's "myth"- almost every one of my piles has a layer of white "ash" looking stuff. I have a few going at a time for many years, and not a one has caught fire.

It's spores of molds/fungus. Yes, this is easily confirmed by microscope or simple chemical test.

All that glitters is not gold. All that looks like ash is not ash. This sounds like some ancient culture determining the origin of lightning or disease or something.

Sounds like actinomycetes

Here is a link that might be useful: actinomycetes

Okay everyone, here's the update on my ash-fungus (this is my new name for it).

I turned the pile again on Friday and did notice that the middle was drier than I would have thought. The ash-fungus was almost completely gone (still a few pockets). As I was rebuilding the pile, I thourghly wet it down again, thinking the whole time that the concept of "a damp sponge" is really elusive and open to interpretation because I had thought I'd wet it sufficiently before. Oh well...moving on.

Like I said the middle was a little dry but smelled good, like "earth" so I was pretty happy, however the bottom smelled like "poo" and was totally mucky! I did get it all turned and after much admiring went inside. Later that night it started to rain....and rain...and...you get the point. All day Saturday, same thing. This morning...same thing. So now I should have plenty of water :-)

My question now is: When would you turn it again? Soon to try and dry it out some now or wait until the surface dries a little on it's on and then turn?

One of these days I'll get this right.

Val

Hi Lloyd:

In answer to your question about whether it was common for Americans to use the term "160 degrees American", no; in all my 46 years I've never heard anyone use 'American' to replace 'Fahrenheit'. Maybe it's a regional thing where herboil lives in Georgia ?