Material is compressed to remove air
The system involves anaerobic fermentation rather than the aerobic action of microorganism in conventional composting to convert food waste into compost. It requires the addition of “Effective Microorganisms”
(EM) which are a mixture of bacteria and yeasts to break down the food waste. These microorganisms will normally include yeasts, (Saccharomyces spp.), lactic acid producing bacteria (Lactobacillus spp.), and phototrophic bacteria (Rhodopseudomonas spp.)
These yeasts, bacteria and fungi will be present in the organic material in compost introduced to the soil. These organisms will be incorporated into the soil web. Materials such as eggshells and bones will also be decomposed but they will take
much longer to breakdown put can be added to the conventional compost bin with the rest of the pre-compost.
The commercially available Bokashi Bin normally consists of a plastic bin with carry handle,
airtight lid and drainage tap. It has an inner drain tray to allow separation of the food scraps and liquid produced by the system and to prevent the solid material blocking the drainage tap. It will often come with a measuring scoop, a push tool and even
a liquid drain cup. Some homemade systems do not include a drainage tap.
The microorganisms are introduced by spreading Bokashi bran thinly on the base of the bucket and over the food during the pickling process. Some systems
recommend putting two or three spoonful’s of Bokashi bran into the bottom of the bucket before adding the initial layer of food waste This is most helpful when a system is being used that does not include drainage. The food should be
added in small pieces to form a layer about 3-4cm thick. Any large pieces should be cut to 3-4 cm to enable the microorganisms to ferment the food effectively and speed up the process. If possible, use fresh food. The Bokashi system will deal with food contaminated
with white mould but green or black. Scatter about a measure or tablespoon of Bokashi bran the top of the layer of waste food and compress it by pressing down with the tool provided or a potato masher to remove air pockets. Cover with cardboard, plastic to
exclude air and close the bin lid. Drain off the Bokashi juice every couple of days.
Repeat the layering process alternating food waste and bran as the waste becomes available, remembering to seal the bucket to exclude
the air on every occasion seal until the bucket is full. Once full leave the Bokashi bin closed and undisturbed for two weeks or more, remembering to drain off the juice every other day.
Two Bin Systems
To work, effectively the system requires the use of two Bokashi bins. The bin in current use is normally kept in the kitchen so that plate scrapings and other food waste can be added directly to the bin. Once full, the
bin is set aside for two weeks and the second bin brought into use.
Bokashi bins are normally kept in the kitchen or utility room but they can be housed in a garage, shed or even in a garden storage box to protect
it from the rain, sun and help protect the bin from frost. However, in colder conditions the fermentation process slows down, so it should be left to digest for a longer period (e.g. for three weeks or more instead of two
Bins are available in the UK in a range of sizes a quick search on the web will show bins of 15 litre, 18 litre, 23 litre, 27 litre, 30 litre (stainless). A pair of bins are normally used so that when the first bin has been filled and
is fermenting a second bin is available to take the current waste. If two bins are insufficient, I would tend to use a third rather than make larger bins. The brand leader in the UK is probally www.getcomposting which works
with Local Authorities to provide residents with low-cost compost equipment. A pair of Blackwall 18 litre bins are on offer at around £20.
However, commercial size Bokashi bins are avialable.
The 120 litre Bokashi bins shown in the photos below are available from a company based in Cornwall (https://www.wiltonecostore.co.uk/) and are suitable for medium
to large scale use with the bins being large enough for restaurants, small businesses, schools and nurseries. The bins shown in one of the photos are being used in a bank of six to meet a local need.
"wheelie bin" Bokashi are also available from:
This size of bin offers such establishments an alternative to aerobic composting and participation in kerbside food collection schemes. As with other Bokashi systems they can be used to ferment vegetable, fruit,
meat, fish and dairy products to make environmentally friendly pre-compost for office communal areas or school gardens.
A larger 140 litre wheelie bin system suitable for commercial & larger scale operators is
available from Bokashi New Zealand (https://www.zingbokashi.co.nz/commercial/)