Vermicomposting (worm bin)

Earthworms (typically Eisenia fetida, 'red wigglers') digest organic waste in a ventilated bin at ambient temperature, producing both finished compost and a separate liquid leachate ('worm tea') drawn off through a tap, a distinct mechanism from the hot compost pile (thermophilic, needs real volume and turning) and bokashi (anaerobic fermentation). Suits small, continuous kitchen-scraps volumes and can be sited indoors or in a sheltered spot rather than needing an outdoor pile. Build cost scales with size, the source's own example is a 300L farm-scale unit; a household bin is far smaller and cheaper.

Cost
Low
Upkeep
Occasional
Skill to build
Basic
Lifespan
Bin structure: 10-20 years; the worm colony itself is self-sustaining indefinitely with proper care, not a wearing asset
Embodied carbon
Low
Space / material use
Low
Output timing
Continuous process
Skill to repair
Basic

Note: Cost, carbon and footprint are rated against the other options for this same need, not in absolute terms.

Inputs

Outputs

Sources

Tutorials

What this page does not tell you

No sizing or quantities: how much a technique yields, and how much a household needs, both depend on the build and the people, so the catalogue compares options rather than dimensioning them. It carries no bill of materials and no build sequence, and it is written for an oceanic, clay-soil climate (Normandy, France). Regulatory notes are indicative and need confirming locally.