Over the past few months, I've been using horse stable sweepings for compost-making. I'm improving my technique through trial and error and some research.

I currently have quite a big heap, and every time I mow my lawn, I then turn the heap, mixing in my fresh grass-clippings for added nitrogen. Once the lawn needs mowing much less often due to winter's onset, I will probably leave the heap alone to finish rotting down over winter.

Initially, every time I turned the heap, I was finding that the hot core of the heap had turned into something that looked like very dry, grey ash. Is that indeed what it was? I presume this was caused by the high temperatures that develop inside the heap, due to microbial/chemical action.

I find that this doesn't occur if I take a broom handle and poke a lot of deep ventilation tunnels into the heap. I initially started doing this because I read that oxygen is required by the microbes that help with the decomposition of the compost. However, I have also read that heat is a necessary requirement for compost-making! However, I would imagine that the kind of heat that turns vegetable matter into ash, would also kill bacteria!

So my question is: Which is more important for making good quality compost, fairly quickly; heat or oxygen? Perhaps the answer is 'a bit of both' in the right balance. What do you think?

Many thanks!

Al