Well after turning over all three bins leaving one empty to turn, I am happy to report that our core temperature is 150 degrees–exactly where we want to be. Like most things there are no hard and fast rules only loose guidelines. Often the trick is to decide which direction to go and avoid vacillation.
It looks like we need to turn our compost every week and build a new bin to accommodate incoming paper from our students. We will use every drop of the compost for spring planting.
Here are the guidelines we have decided to follow… remembering that we are a 3/4 acre farm in the middle of a community that would not appreciate us attracting pests….
-Hot compost- core temperature 140-170
-Turn often and thoroughly about once a week- the goal is to incorporate what is on the outside edges to the center (this will not slow down heat and in fact will encourage it)
-Do not add anything new to bins in progress
-60-70% decomposition should occur
-Moist is good but sopping wet is not good (usually with an open bin system like ours rainfall is sufficient but in dry spells add some water)
-Ratio is somewhere between 10:1 and 20:1 brown or carbon to green or nitrogen (in our system coffee and fresh weeds and grass are large contributors of green and straw, paper and dried weeds and grass are sources of brown)
-The smaller pieces added the better and quicker the compost progresses
-Make sure compost is finished cooking before adding to beds or plant growth will be hampered