Lloyd

Both have one or two benefits over the other, but the above factors will probably be more important in deciding which way to go. And it is not as simple as just hot versus cold; materials, weather, bins, time available to check and turn pile, these all affect the core temp.

My highest core temp is around 165F; over a period of ten years in the same climate (zone 6). The 165F is a summer number, winter core temp runs about a max of 140F. These numbers are for a good mix of small pieces and a bin large enough to retain heat well.

Some folks will say, Oh a temp of XXX is too high. But a core temp is a reading at just one point in time. So I make a optimal pile and get a core temp of 165F after three days. But even if I turn and water the pile every few days, each successive time the core temp will be a bit lower. Maybe it would more accurate to say a pile with a high core temp of 165F had an average core temp of 145F?

mysecret: your pile is about 32 cu ft., which is over a cubic yard, but it might heat up a bit more if it was more in the shape of a cube. A sphere is the most efficient, but difficult to achieve for the average garden engineer. :-] But your pile is certainly big enough, so I suspect the brown/green mix + moisture + air has more to do with it right now than its shape.

It may take two years to compost, but your better off with the cold composting method. It is the least labor intensive way. Not everyone wants to hand turn compost, or use machines that are worth way more then the compost! ;)

Lloyd

Maybe some should try a bit of both to see what fits best for them. This is a post about temp so I dont want to change the subject.

Nice link Lloyde

A fall mix of sweet gum, oak, and maple leaves is a very easy hot pile, in my experience. I run over them three times with the mower and bag them with some grass. Almost a perfect mix without any other ingredients. My two bins are 4' by 8' by two feet high. When the core temp rises to 130 or 140F, I turn it, adding a mist of water as necessary. It only takes a minute each day to stick the compost thermometer in the pile.

The patience level of the gardener may determine whether one is best suited for cold composting, or too impatient.

I love reading about the stuff some of the more organized precise composters do... and the number of words I've added to this comp's spell check dictionary from this forum.

Regarding pic, the black bags are pine needles, waiting to join the next pile. I dumped a few of the bags and decided that was enough in ratio to the other stuff. This was a set it & forget it pile that was 6 ft. high when it was finished being assembled. I think this pile probably got hot in the center at some point because I made an effort to put layers of green/brown.

Just out of the pic on the left is a plastic 55-gal drum that's a compost bin also, where I've dumped everything since assembling the big open pile pictured. It's mostly kitchen greens, browns are just uncommon during the summer. The drum is probably too anaerobic to get hot, if I understand that part correctly.

If the mix does not seem too wet, add some grass or other green in. You mentioned 'shredded leaves' but leaves run over with a mower once barely qualify as shredded. I run over maple and sweet gum leaves two or three times before using them in the compost pile. Oak is dryer and a bit harder to shred, so at least three times. When my chipper/shredder is working, one pass reduces them to a tiny 1/16".

If you do shred stuff with a mower, change the oil and air filter much more often.