Wormkasten

Wormkasten, literally "worm box" in German, is a worm bin used for vermicomposting. In home vermiculture, red wigglers (Eisenia fetida or Eisenia andrei) are common because they tolerate crowded bins and rapidly degrade kitchen waste. The result is vermicompost, a dark, crumbly fertilizer, and a reduced waste stream.

A typical wormkasten consists of one or more shallow trays or a single bin with bedding and an upper feeding area. Bedding includes shredded newspaper, cardboard, coconut fiber, or leaf mold, kept moist like a wrung-out sponge. Kitchen scraps are added in small amounts and buried under bedding. The bin is kept in a cool, shaded location; temperature should stay roughly 55–77 F (13–25 C). Moisture should be high but not soggy to maintain aerobic conditions.

Worms digest the organic matter and produce castings for the soil. The system may also yield a liquid called worm tea if a leachate is collected; use it cautiously after dilution. Harvesting involves separating finished castings from worms, often by moving the worms to a new tray and letting the castings settle, or by manual separation.

Common problems include odors from overfeeding or poor aeration, mold, or pests. Fixes include reducing food amount, adding dry bulking material, mixing bedding to improve aeration, and adjusting moisture and location. Proper management yields a steady production of castings and ongoing reduction of household waste.