Bokashi vs Wormery: Food-Waste Systems Compared

Illustration of a stackable tray wormery in a sheltered garden corner

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Bokashi and wormeries are both small-scale systems for processing kitchen waste at home, but they rely on completely different biological processes. Choose a wormery if you mainly have vegetable scraps and want finished worm compost from one managed system. Consider bokashi for a wider range of food scraps only when you also have a suitable place to finish decomposing its fermented contents.

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What a wormery does

A wormery, or worm bin, uses composting worms to break down kitchen waste and small amounts of soft garden waste. The RHS worm composting guide describes a typical wormery as having at least two compartments: a lower sump that collects liquid, and an upper area where the worms feed and work. Single-compartment wormeries are also used.

Buy composting worms from a wormery supplier. These species live in decomposing organic material; ordinary deep-burrowing garden earthworms are not a suitable substitute.

What you can feed a wormery

The RHS lists suitable inputs:

Raw vegetables, except onions, shallots, leeks and garlic, which are best used in small amounts or cooked first
Cooked vegetables
All fruit, except citrus peel, which should be limited or preferably cooked before adding
Tea leaves or home-compostable tea bags, eggshells, coffee grounds and small amounts of bread
Limited amounts of newspaper, shredded office paper and cardboard, but not glossy magazines
Small amounts of soft garden waste such as annual weeds, leaves and other green material

You should avoid dairy products, fat, grease, meat, fish and bones, because these attract pests and flies. Large quantities of tough leaves or woody material will slow the system down. If you have a lot of garden waste, the RHS recommends running an ordinary compost heap alongside the wormery.

Wormery outputs

A wormery produces two useful materials. The solid worm compost can be used as a general soil conditioner or as a constituent of homemade growing media; it is generally rich in nitrogen and potassium. The liquid drained from the sump can be used as a liquid fertiliser after diluting with water at a rate of 1 part liquid to 10 parts water. Its nutrient composition will vary.

Wormery maintenance and practical limits

Composting worms are most active between 18–25°C. Activity declines noticeably below 10°C and above 30°C, so the wormery should be kept in a shed or sheltered spot that avoids winter cold and summer heat. The RHS warns that a neglected wormery kept in a kitchen, utility room or balcony can sometimes produce odours.

Feed small amounts often, chopping waste into smaller pieces. If waste is not being eaten, stop feeding for a few days. An established wormery can be left without food for up to four weeks, but liquid may accumulate and must be drained to avoid waterlogging. Occasionally fork the compost gently to check the worms are present and healthy.

A wormery is usually emptied when full, which takes about 8 to 12 months. You must separate the worms before using the compost. Many wormeries use stacking trays so the worms work upwards, leaving finished compost in the bottom tray; this reduces sorting, although you should still check the harvested tray for remaining worms.

What bokashi does

Bokashi preserves food scraps by fermentation in a sealed container using a suitable microbial starter. For example, Skaza’s Bokashi Organko guidance accepts cooked food, meat and dairy as well as fruit and vegetables. Its two-bin method leaves a full bin sealed for at least 14 days while the second receives new scraps; the fermented material then needs further decomposition in soil or compost.

Bokashi bins are typically sealed containers. Food waste is fermented anaerobically with the help of a microbial starter, often supplied as a bran or spray. The process produces a liquid that can be drained off, and a fermented mass that is not finished compost. That material usually needs to be added to a conventional compost heap or buried in soil to complete decomposition. Follow the manufacturer’s guidance for starter quantities, fermentation time and disposal of the fermented material.

Direct comparison: bokashi vs wormery

Feature	Wormery	Bokashi
Process	Aerobic composting by worms	Anaerobic fermentation with microbial starter
Inputs	Raw and cooked vegetables, fruit (citrus limited), tea bags, eggshells, coffee grounds, small bread, limited paper/cardboard, small soft garden waste. Avoid meat, fish, dairy, fat, bones.	Can include cooked food, meat and dairy in systems such as Bokashi Organko; check the chosen system’s exclusions.
Outputs	Worm compost (soil conditioner) and liquid fertiliser diluted 1:10	Liquid requiring dilution according to guidance, plus fermented solids needing a finishing stage
Maintenance	Feed small amounts often; drain liquid; keep at 18–25°C; check worms; harvest when mature; timing varies with system and feeding	Drain liquid regularly; keep container sealed; add starter as directed; no worms to care for
Space and location	Needs a sheltered outdoor or shed location; not too hot or cold	Compact and sealed, so often kept indoors, but may produce odours if neglected
Ongoing supplies	Bedding material and suitable food; replacement worms only if needed	A continuing supply of the specified microbial starter

Practical limitations and decisive checks

The RHS is clear that a wormery is not a substitute for conventional composting. It cannot handle large volumes of garden waste, and it needs a stable temperature range. If too much waste is added, the wormery may smell and attract flies or vermin. Excess liquid must be drained, and if the contents become too wet, add shredded paper or card to absorb moisture and increase air circulation.

For bokashi, an important practical limitation is finding somewhere suitable to finish decomposing the fermented solids. The collected liquid also requires appropriate dilution if used as feed. RHS homemade-fertiliser guidance suggests 1 part bokashi liquid to 100 parts water (10 ml per litre). Follow any more dilute recommendation for the chosen system; nutrient strength varies and this is not a complete, standardised plant feed. The fermented solid material is not ready to use directly on plants; it needs further treatment. Allow space and time for that finishing stage before buying. Do not place freshly fermented food directly against roots or mix it into an occupied pot; follow the system’s incorporation and waiting instructions.

Choosing between the two

If you have a suitable sheltered location and want to harvest a soil improver without a separate fermentation-finishing stage, a wormery is the more direct option. It suits households that generate mostly vegetable and fruit waste and can manage a living worm population.

If you have very limited outdoor space, want to process a wider range of food waste including cooked scraps, and are prepared to follow a manufacturer’s instructions carefully, a bokashi bin may be more practical. However, you will still need somewhere to bury or compost the fermented material, and a second bin may be needed while the first ferments.

Neither system replaces a conventional compost heap for garden waste. The RHS worm composting guide explicitly says a wormery is not a substitute, and the same logic applies to bokashi: both are best seen as kitchen-waste processors that complement, rather than replace, ordinary composting.

Useful products for this job

The links below open Amazon UK product searches. Check the exact item, seller, current price and compatibility before buying.

Stacking-tray wormery: Stacking trays can reduce worm sorting when harvesting mature compost; a sump and tap support liquid management. Check drainage, lid and sump access, tray weight when full, and whether composting worms and bedding are included. Search Amazon for Stacking-tray wormery.
Bokashi bin with drainage tap: Bokashi bins need an airtight seal and a tap to drain the liquid fertiliser; starter bran is usually required. Ensure the lid seals tightly, the tap is accessible, and you can obtain the correct microbial starter; check manufacturer's instructions for waste types and fermentation time. Search Amazon for Bokashi bin with drainage tap.

Related garden guides

Sources and further guidance

Guidance researched in September 2026. The feature image is an AI-generated illustration. Product guidance is based on published information, not hands-on testing.