Summer Compost Progress

Earlier this week we advanced the summer season’s compost pile to the next phase of its decomposition, a really exciting milestone in its progress towards finished compost — our goal is to share 100% of the summer compost with our composting community members and we’re eager to bag it!

The aerobic composting uses three bins (and a separate worm house, more to follow) and the biggest development was moving 75% of pile 1 to the second bin. This was a chance to re-mix, fully aerate, and adjust the moisture.

Photos showing construction of bin 2:

I moved the pile to bin 2 on Monday and yesterday the temperature was still ~130 (see photo above), so it’s a very active, hot pile. I’ll continue to turn and re-mix this pile without adding any new material until the core temperature drops near ambient, then I’ll sieve the mixture and move to a third bin to cure.

Meanwhile, we’re collecting between 1/4 and 1/3 ton of residential food waste each week and adding chipped wood and water to form our pile. We also add Azomite mineral dust to our pile because we believe that re-mineralization of soil is essential for plant health.

Food layer with dusting of Azomite

One amazing aspect of composting is watching the pile of waste food & wood heat and shrink. On average, industry studies show that piles of food waste will lose around 25% of initial mass (and decreases in mass of up to 35% have been seen) while reductions in volume are routinely between 40-50%. The small (but growing!) percentage we feed to worms is substantially transformed into new worms with very few pounds of castings harvested.

I’ll keep posting photos and temperature stats on the two bins.