Bokashi, compost or vermicompost: which method should you choose for your kitchen waste?

Print

Bokashi, garden compost bin or wormery: all three methods recycle kitchen waste, and they are often presented as interchangeable. They are not. They do not work in the same way, do not accept the same leftovers and do not produce the same thing.

This guide compares them from the bokashi point of view: what it does better than the others, what it cannot do on its own, and how to combine it wisely. For an overview of all the options, including effective micro-organisms, see also our guide Compost, vermicompost, bokashi or EM: which method to choose.

Three processes, three approaches

• Composting is decomposition in the presence of air. Bacteria, fungi and small creatures consume the material as they breathe. The heap heats up to a greater or lesser extent, loses a lot of water and carbon as gas, and ends up as mature compost after several months.
• Vermicomposting is also decomposition in the presence of air, but most of the work is done by compost worms, together with the micro-organisms in their digestive tract. The result, vermicompost, is a fine, ready-to-use soil improver.
• Bokashi is fermentation without air. In a sealed bucket, lactic acid bacteria acidify the waste, which is preserved rather than decomposed. The result is a pre-compost that must then go into the soil. Our guide What is bokashi? explains this process in detail.

That is the key difference: compost and worms transform waste, whereas bokashi prepares it. It covers the first half of the journey, quickly and in very little space, but it always leaves the rest of the work to the soil.

The comparison, point by point

Space

• Bokashi: a 10 to 20 litre bucket in the kitchen, ideally two.
• Wormery: several trays stacked on top of one another, or a bin of a few dozen litres, indoors or under shelter.
• Compost bin: a bin or heap in the garden, standing on the soil.

Accepted waste

• Bokashi: almost all solid food leftovers, raw or cooked, including meat, fish, cheese, citrus fruit and onions. No garden waste.
• Wormery: mainly raw peelings, in moderate amounts. Worms do not like meat, citrus fruit or anything from the onion family.
• Compost bin: peelings and garden waste in large volumes. Meat, fish and dairy products are not recommended or should be limited, mainly because of smells and rodents.

Time

• Bokashi: the time it takes to fill the bucket, then at least two weeks of fermentation, then two to four weeks in the soil before planting. It can sometimes take up to two months for everything to be absorbed.
• Wormery: three to six months for the first harvest, then roughly one harvest a month.
• Compost bin: four to nine months in a bin, often longer in a heap.

Smells

• Bokashi: faint with the lid closed, sour and vinegary when opened. It is not "odour-free", but good fermentation never smells rotten.
• Wormery and compost bin: a woodland-floor smell when well balanced, unpleasant smells when too wet or poorly fed.

Upkeep

• Bokashi: sprinkle, press down, close, drain the liquid every two or three days, then bury. Never stir.
• Wormery: feed regularly, keep an eye on moisture, harvest.
• Compost bin: balance green and brown materials, aerate from time to time, water in summer.

Long-term cost

• Bokashi: buying the bucket, then an ongoing supply of activator, bought or home-made.
• Wormery: buying the bin and the worms, then next to nothing, since the worms breed.
• Compost bin: a bin, or nothing at all for a heap.

What you get

• Bokashi: an acidic pre-compost that must never be used as it is, and a liquid to be heavily diluted.
• Wormery: ready-to-use vermicompost and a liquid to be diluted.
• Compost bin: mature compost to spread on the vegetable patch or mix into potting compost.

Did you know?

In a large-scale trial on roadside grass cuttings, carried out with an EM product manufacturer, fermentation under a tarpaulin lost only 2 to 5% of its organic matter in six to eight weeks, compared with almost half for windrow composting. Nitrogen, meanwhile, was almost entirely retained, with losses of 0 to 2%, whereas the compost lost 10 to 16%.

Meat, fish, dairy: bokashi's strong point

This is the reason people choose bokashi. Leftover meat, fish and cheese, saucy plate scrapings or small bones attract rodents and flies in an open compost bin, and worms will not touch them. In the airtight bucket, they ferment like everything else, out of reach of animals.

A few precautions are still needed: cut pieces small, sprinkle a little more bran over protein-rich leftovers, and avoid liquids and large bones. And do not assume that fermentation makes these leftovers harmless to animals: once in the garden, they must be buried well.

What bokashi cannot do on its own

The pre-compost that comes out of the bucket looks like slightly softened waste and it is acidic. Left on the surface or used as a mulch, it attracts animals and can damage roots. So it always needs a finishing stage:

• garden soil: bury it 20 to 30 cm deep, mixed with the soil, away from roots, and wait at least two weeks before planting;
• a soil container, on a balcony for example, if you have no garden: see our guide No garden? What to do with your bokashi;
• a compost bin, where it mixes with brown materials;
• worms, in small amounts.

As for the end result for plants, do not expect miracles. In a pot trial comparing bokashi and compost made from the same waste, only one comparison out of sixteen clearly favoured bokashi. Both methods feed the soil in a comparable way: the difference lies mainly in the type of waste accepted and the space required.

Key points

Bokashi replaces neither the compost bin nor the worms: it complements them. Its real strength is accepting all kitchen leftovers in very little space; its limitation is that it must always end up in the soil.

Combining methods

Bokashi and compost bin

This is the simplest combination in the garden. The bucket takes meal leftovers, meat, fish and citrus fruit; the compost bin takes raw peelings, grass cuttings and leaves. Once fermented, the contents of the bucket go into the compost bin, spread in a layer and covered with brown materials. All the details are in our guide Bokashi and garden compost.

Bokashi and wormery

In a flat, the wormery takes raw peelings and the bokashi takes the leftovers the worms refuse. The pre-compost can then be given to the worms, but in small amounts and in one corner of the bin, because it is acidic. Results vary from one household to another: we explain how to go about it in our guide Bokashi and wormery.

Our advice for your type of home

Flat with no outdoor space

A wormery, such as our WORMbox Wormery, remains the most self-sufficient option, as it produces something ready to use. Bokashi only makes sense if you have a regular outlet for it: a community garden, a friend's or relative's plot, or a neighbourhood compost bin that accepts it.

Flat with a balcony

Both work. Bokashi can be finished in a large soil container or deep planters, provided you are patient before planting. If you are unsure, our guide Wormery or traditional compost bin will help you pin down your needs.

House with a garden

The compost bin remains the foundation, because it also takes garden waste. A bokashi bucket such as the Comfort Bokashi Composter complements it very well for all the awkward kitchen leftovers, which you can bury directly in your vegetable beds.

Emy's tip

Before choosing, spend a week noting what you actually throw away. If your bins contain mostly raw peelings, worms or a compost bin will be enough; if they contain lots of meal leftovers, meat or cheese, bokashi will earn its place.

In summary

Compost and vermicompost transform waste in the presence of air and deliver a finished product within a few months; bokashi ferments it in a sealed container in around two weeks, but delivers a pre-compost that still has to go into the soil. Its main advantage is that it accepts almost all food leftovers, including meat, fish and dairy, in a simple kitchen bucket. In the garden, it is the ideal companion to a compost bin; in a flat, it really comes into its own alongside a wormery or a soil container. Choose according to your waste and to where your bokashi can finish its journey.

Related products

Bokashi Composter Skaza Organko 2

Capacity 9.6 litres, sold individually or in a set of 2

€83.01

Urbalive Bokashi composter

Capacity 10.6 litres, available individually or in sets of 2

€80.97

Skaza Essential Bokashi Composter

Capacity 15.3 litres, set of 2 buckets

€78.93

Best Seller

Bokashi EM compost activator | 1 kg bag

Individually or in sets of 2 or 3 bags

€8.15

Other topics in the guide

Vermicomposting30 sheets →Composting25 sheets →EM micro-organisms26 sheets →