Compost creation & heat

I'm trying to create my first ever compost with one of those tumbler composters and I'm curious about heat generation.  I've read that internal compost heat only gets generated when the pile is 3'x3'x3' or thereabouts.  I don't have that much stuff in the composter yet.  But sometimes it gets enough sun and warmth that it gets fairly warm.  I also have it covered with a tarp to keep rain from getting in so I can better control the water it gets, and that also helps keep it warm.  And I imagine this summer it will be able to get pretty hot.

I'm curious if anyone can help me understand the "heating" side of composting.  When they talk about compost "heating up", I always asumed it was a chemical process within the pile itself.  Can this internal process be "kickstarted" by external processes like weather and outside heat?  Does tumbling the compost restart this internal heating from scratch each time it is turned?

I would like to know more about this, too. 

Buying the Lifetime double tumbler...  though it'll take awhile to come and then I have to decide where to put it, but it's not 3x3... 

So I assume we need another big pile or more than one that'll meet the 3x3 rule.   Pretty sure that the double tumbler will not meet all needs? 

I don't have a complete picture in my mind of a good compost operation.  I have on my todo list to read here, go back to OhioGardener's posts, and also rewatch a beginning gardener's how-to seminar I saved on composting. 

I also want to watch or read more about "Regenerative Gardening" and see what they say about composting.  I know there was discussion about hot and cold compost methods. 

Learning about composting has come a long way from my 40 year old knowledge and my first compost bins.

goodtogrow wrote:I'm trying to create my first ever compost with one of those tumbler composters and I'm curious about heat generation.  I've read that internal compost heat only gets generated when the pile is 3'x3'x3' or thereabouts.

The cubic yard applies to compost piles, not compost tumblers. Compost tumblers are a "closed environment" and the material will quickly heat within the tumbler.   When I start a new tumbler bin with kitchen scraps, juice bar pulp, coffee grounds, and pine pellets, it will typically show a temp of 140ºF to 160ºF the second day after starting it. If it is in that range on the thermometer, it gets turned.

I'm curious if anyone can help me understand the "heating" side of composting.  When they talk about compost "heating up", I always asumed it was a chemical process within the pile itself. 

The heating of the compost is basically due to the microbes digesting and pooping the organic material. The greater the microbial life, and the better balanced the greens and browns, the more the heat.  It is not a chemical process, but an activity process.

Can this internal process be "kickstarted" by external processes like weather and outside heat?

No, it cannot be kick started by any external process, with the exception of adding a scoopful of previously finished compost to jump start the microbe reproducing process in the new compost. The ambient temperature can affect the process if the sun gets so hot that it "cooks" the compost, and kills the microbial life, or if it gets so cold that it freezes the compost.

Does tumbling the compost restart this internal heating from scratch each time it is turned?

 It doesn't restart the heating process, but rather spreads the heat out to the areas that were not being worked by the microbes. The center of the compost becomes the focus of the microbes as the digest the food and reproduce, but microbes have a very limited ability to move about (unless they are in water such as "compost tea") and if they are left in one area too long they start dying or going dormant. When the tumbler is gently, slowly turned, it distributes the compost from the center of the compost to the outside edges and vice versa. This gives the microbes new food the feast on, which starts reheating the compost.

Note 1: When I finish filling a bin of the tumbler, it begins its 30-day composting process and is left alone except for periodically checking the temperature and turning the tumbler.  Any time new material is added a bin of the tumbler, the clock restarts on the 30-day composting since a new food source was added.

Note 2: When I start a new bin of the tumbler I normally sprinkle in half cup or so of rock dust to the food scraps. The rock dust is not added because the compost needs it, but is added to provide trace minerals that the microbes thrive on. Many will tell you this is totally unnecessary, and it may well be, but I always have a bag or two of Azomite sitting around and don't mind using it.

Thank you very much for explaining that, OhioGardener, that helps me a lot.  I'll have to pick up a compost thermometer and use it.

You mentioned using pine pellets, could I use the kind used for burning, like these?

I'll add my thanks. Exactly the answers to provide clarity.

goodtogrow wrote:You mentioned using pine pellets, could I use the kind used for burning, like these?

No, I would not recommend it.  Pine Pellets are sold for horse bedding, and they are nothing but compressed pine sawdust. 

Pellets used for stove burning contain all types of sawdust scrap from a sawmill. They may be oak or maple or walnut or pine, etc., or any combination of those. Hardwood sawdust will take a long time to break down in the compost tumbler, and if the pellets are from walnut they will add a toxin to your compost that serves the purpose of keeping other plants to grow.  Additionally, depending on who sourced the sawdust, they may have been sawing treated wood for making pallets, and that treated sawdust will go into the pellets.

I only use bedding pine pellets which I buy at either Tractor Supply or Rural King. Any store that sells horse feed and/or bedding will have bags of pine pellets.

https://www.tractorsupply.com/tsc/product/tractor-supply-pine-pellet-stall-bedding-40-lb?cm_vc=-10005

Ohio Gardener - I am slowly thinking about buying a tumbler, Maybe.  But my question is, if given your above list of ingredients, about what percent of the total do the pine pellets represent.

Okay, thanks again, OhioGardener, I will look around for that type of pellets.  I really appreciate all your help, it has taken me awhile to learn about composting, but you've really simplified a lot of it for me.

yolos wrote:Ohio Gardener - I am slowly thinking about buying a tumbler, Maybe.  But my question is, if given your above list of ingredients, about what percent of the total do the pine pellets represent.

I'm new, but I think I have this right:  You want 1 part greens to 2 parts brown in your compost, and those pine pellets that OhioGardener is talking about are considered browns.

goodtogrow wrote:

yolos wrote:Ohio Gardener - I am slowly thinking about buying a tumbler, Maybe.  But my question is, if given your above list of ingredients, about what percent of the total do the pine pellets represent.

I'm new, but I think I have this right:  You want 1 part greens to 2 parts brown in your compost, and those pine pellets that OhioGardener is talking about are considered browns.

Yes, you are correct, but....    The pine pellets are compressed, much like the bales of peat you buy, and when they are expanded they are several times their original size.  I have a plastic Folgers coffee can that I use to measure out the pine pellets. The coffee can originally had 51 ounces of coffee grounds.  I start by adding one can full of pine pellets to a 5 gallon bucket of juice bar pulp or kitchen scraps.  If I see that the compost is too moist or not starting to break down, I'll add a couple more handfuls of pine pellets.

Besides that, I find the Folgers Coffee cans are very handy for storing various gardening things like bone meal, blood meal, find vermiculite, etc.
 

Thanks OG.  I think I asked you this before because I now remember you showing the Folgers Container.  I have been able to get my 3x3x3 compost pile cooking (now 150* and need to turn it) but I can never get my compost tumbler heating up.  I think I may break down and fork out the money for a Jora.

Yolos, I was going to suggest you look on Craig's List or Marketplace for a good used one, but there was only one double-chamber in Macon. I guess the rush for all things gardening is still in full swing.

I was happy with my 80-gallon Lifetime tumbler. I liked it because of the triangle inside with a bar that insured the contents didn't just spin in place.

OhioGardner, what do you think about this product for composting?

https://www.mrpets.ca/online/eagle-valley-talon-abm-pine-pellet-35lb

goodtogrow wrote:OhioGardner, what do you think about this product for composting?

https://www.mrpets.ca/online/eagle-valley-talon-abm-pine-pellet-35lb

The description looks like it is essentially the same thing as the pine pellets from Tractor Supply Co., with the main difference being the cost.  TSC sells 40# of pine pellets for just over $5.00, and these are 35# for a $7.69.  Other than that, they look like the same thing.

https://www.tractorsupply.com/tsc/product/tractor-supply-pine-pellet-stall-bedding-40-lb?cm_vc=-10005

Okay, great, thanks.  So it should be good to use as a brown in my compost, then, correct?

goodtogrow wrote:Okay, great, thanks.  So it should be good to use as a brown in my compost, then, correct?

Yes, according to the description on their site. Nothing bad in it.

Thank you, OhioGardener, much appreciated!

Holy cow does that pine pellet bedding stuff ever expand!
I think I put too much in. 

I did read what you wrote about putting it into another container and checking it first because it expands.  But I didn't realize you meant with water (I think you meant with water?).  And, well, I also might have simply forgotten about that step.  Because after I added water it expanded a lot.  This stuff at least doubled in size, if not more, haha!

Last night I put in a layer of the pellets and then some vegetable scraps and coffee grounds (around 4-5gal of grounds), and then another layer of the pellets.  Maybe 2-3" worth on each layer.  Then I soaked it all last night with a reasonable amount of water.  Today, around 24hrs later that top layer of pellets alone is almost 6" deep!


And I imagine the lower layer of pellets is the same.  The stuff just absorbs water and then dries out and gets huge.  It's rather amazing, really.  I get why it's used as animal bedding!  I was worried that my compost tumbler wasn't getting full of stuff fast enough.  Well, I'm no longer worried about that - I'm just worried there's way too much brown in it now!

Oh well, lesson learned.  I found it more comical than anything else, to be honest.  I guess I'll have to find more coffee grounds and other greens.

Any advice or just add more greens?  Did I ruin my compost tumbler?

goodtogrow wrote:Any advice or just add more greens?  Did I ruin my compost tumbler?

Did I mention that the pine pellets expand several times their size?

No, you didn't ruin your tumbler, as long as it is not over-filled to the point that it can't tumble the contents.  You probably need more green added, but you might want to wait a couple days and check the temp. If it is hot, you are in good shape, and it will begin composting down.  But, if it is still cool that means there is too much brown, and not enough green -- add something like alfalfa meal/pellets, coffee grounds, or fruits/vegetables without any more browns.

Okay, that's good news, then.

Yes, you did mention, I just happened to forget that (important) part

I have yet to get a thermometer, though.  Hopefully soon.  I was looking at this one (unless you know of a good one?):
https://www.amazon.com/Reotemp-Instrument-Corp-Compost-Thermometer/dp/B002P5RGMI

Thanks, I shall press on regardless!

That is basically the same thermometer I have. Mine is 18", but other than that the same. It works well.

Ok, thanks.  I'll pick one of those up, then.