How large is your tumbler?

Lloyd

7 cubic feet

here is the link

Here is a link that might be useful: mash here

I'm guessing the volume is not large enough to get into true thermophilic composting. Your mix sounds fine and if the moisture is in the range of 40-60% it would normally heat up nicely but small volume piles don't have the mass to generate great quantities of heat. In any event, your material will compost, albeit at the mesophilic stage. I have a small drum that doesn't generate heat either but it produces nice 'post all the same.

Lloyd

I thought about putting some alfalfa in there or blood meal but for the meantime ill just keep adding coffee grounds as i use them and keep it turned. For future reference im gonna try to break down the leaves into smaller pieces. Do you think that the grass clippings i added from november (which were fresh cut green) have turned into like straw or hay and would not be considered a brown? I really expected it to be further along by now but i figured with the winter it was slowing it down

Just keep doing what you have been and it will soon take off if i know Al weather. Yes,at this point the grass is more carbon than it was origionaly but it's still viable.

I'm new to composting and spent a lot of time reading and asking a few questions on here (many experts). I set up 2 Tumblers I picked up for free. One about 40 gallons and one about 89 gallons. I started the 40 gallon one weeks before I snagged the 89 gallon one. Threw all the ingredidents in and tumble it. Not much going on in this pile, especially with the colder weather.

When I got the 89 Gallon one, I elected to layer the Greens (coffee ground, fruit scraps, chicken manure) in between the browns (leaves) with no turning (about 70 gallons of ingredients). This one has been a consistent 100 degrees in the middle when I check.

Just kind of an experiment, but falls into much of what I have been taught in this forum (mass, etc.)

The minimum compost pile size I have found that will start to heat up is 27 (3 x 3 x 3) cubic feet. Piles smaller then that will, eventually, become compost but have not, in my experience, generated any heat.

It took three loads with my tumbler before I got a temp of 160F. It was too much work for the amount of compost made, so I gave it up after a year and a half. The center bar broke after four years of use, and I gave it away.

I have been using mesh bins for ten years with excellent results. I started with 4' round bins 24" high; and now have two 4'by8'by 24 to 30" high. The min size one needs for a bin to generate and RETAIN heat, depends somewhat on which materials are used. For example, a compost pile made of leaves can be smaller than one made of wood chips. The heat moves thru wood chips easier than finely shredded leaves.

I use shredded leaves because it works well and is available. The leaves are reduced by my mower four times if my chipper/shredder is not available. And not all shredders reduce to the same degree.

My tumbler came with a compost thermometer 18" long, and that is still a valuable tool in composting.

A huge size compost pile will not create and retain heat if the basics of hot composting are not present. That means proper C:N ratio, small particles, moisture in the correct range. And turning and watering at the proper times. Going by a volume of 1 part green to 2, 3, or 4 parts brown might not cut it, especially in a tumbler.