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Microbial Campus: Propagating Bokashi

2016 Rooftop farm at University of Hong Kong and students’ households

  • Workshop program ‧ indigenous microorganisms ‧ sensory agroecologies ‧ communal resource cultivation

Guest lectureship at the General Education Unit and campus' Rooftop Farm, in collaboration with Wanho Tam, Six Hang, Celeste Shai, Research Institute for Organic Treasures (RIOT) and Tawaraya Rice Mill 香港精米所 俵屋玄兵衛.

In this campus-engaging upcycling of food ‘waste’, participants were taken to the university’s bamboo groves for sampling traces of mycelium, and to the canteen to scavenge leftover rice. The rice starch served as attractant for the yeast strains in the mycelium. In addition with molasses, sauerkraut brine and water, this concoction was marinated into bran—rice milling residue (米糠). Participants took a bucket of this self-propagated bokashi home with the assignment to collect kitchen scraps. This bokashi-fermented food ‘waste’ was eventually devoured by the earthworms on the campus farm’s compost pile.

Curing first batch of DIY-bokashi on rooftop farm of Hong Kong University.
Collecting rice bran from local rice mill (usually destined for landfill).
Scavenging tiny bits of bamboo rhizome and leaves on campus.
Packing bamboo residues for mycelium propagation.
Leftover rice from student canteen serves as attractant of mycelium.
After one week the mycelium (fluffy yeast strains) emerges atop rice.
Collective curing of rice bran with mycelium-lactobacilli concoction.
Homework assignment; collect food scraps and return full bucket.
After fermentation, the material is worked into the compost.
Biopedagogic Mobilisation
Indigenous bokshi from rice bran, propagated bamboo mycelium, and lactobacilli.
Biopedagogic Mobilisation
Ethereal oils in rice bran make the curing a delight for skin and nose.
Biopedagogic Mobilisation
Bokashi as part of regenerative, urban resource cultivation.


Generating our own Bokashi compost-bedding from scratch — solely with local inputs — was a delightful and socially engaging way of learning about foodwastereduction. This small but applied ‘change experiment’ starting at my house showed me that we can indeed set new precedents for how to re-organize our urban lives.

— Law student at HKU —

The learning and hands-on experiences from your workshop were super useful, since I am working at the Mahjong Hostel. Now we are able to compost our kitchen scraps on our downtown rooftop in a smell-free way, and we are much more motivated to keep going.

— Chef at Mahjong Hostel in To Kwa Wan —

Your workshop is helping me to reduce my carbon footprint in very concrete ways. At my rural home, I started to make biochar from woody residues, ferment all my kitchen scraps and toilet wastes for returning them to the soil. Thanks for providing such inspiration and advise.

— Garbage reduction activist and part-time farmer —

By sampling traces of mycelium in the bamboo groves on campus, utilizing foodwaste from our school canteens, and seeing the enthusiasm for recycling among ourstudents, I rediscovered in this workshop the underutilized possibilities we have at our university.

— Programme director General Education Unit —