PVC pipe stack being pulled out of a backyard dalek-scale Johnson-Su bioreactor…. like looking into a Hitchcock movie!

presoaked woodchip, cocoa shell mulch, yard and grass trimmings, kitchen scraps and limestone dust to make the pile, it’s pretty low on nitrogen i think, so might not be ready until Spring 2024…..

Johnson-Su Variations on Dalek Compost Bin

Experimenting with some of the principles of the Johnson-Su composting method at the scale of the backyard compost bin. Johnson-Su bioreactors produce a highly fungal-based compost insofar as the pile is not turned at all during the process. Because there is no turning, adequate aeration is maintained with the introduction of airstacks, which allow for a vertical column of air to be generated. Once the compost heats up and ‘sets’, the airstacks are removed leaving a negative space through which passive aeration may continue for the full period of composting. With the smaller scale of the backyard dalek bin, I’ve added the potential for a bicycle pump to act as a low-carbon technique for actively adding air to the stack. Finally, once the thermophilic phase of the compost is completed, worms are added to the pile for a more diverse and complete microbial mix in the resulting compost.