Bokashi bins are used to process kitchen waste, including meat, fish, dairy products and cooked food, into a useful garden soil conditioner. The system uses a bran mixture infused with micro-organisms which is combined with the organic waste materials in a sealed container. The contents are then fermented anaerobically. (See our post on Bokashi composting for more details)
The easiest way to begin bokashi composting is to buy a pair of purpose-made bins. These are usually made from recycled plastic and work really well, but home-made systems can work too. Catering size food containers are ideal and may be available at recycling centres, or suitable bins and taps can be purchased from home-brew supplies shops and home improvement stores.
It’s vital that containers have a good air-tight lid for the process to work properly. Also, the fermenting waste needs to be separated from any liquid draining through. The most basic DIY option is simply an air-tight lidded bucket with no tap. It will do the job of fermenting the food waste, but will need 1-2 inches of shredded paper or sawdust in the bottom to soak up any liquid produced during the fermentation process, and all the waste added will need to be as dry as possible.
A better system has a reservoir in the bottom of the container below a drainage grid, plus a tap to draw off the liquid. Taps can be purchased from home-brewing suppliers or garden centres. You will need to drill a hole near the base of the bucket to fit the tap. Alternatively, use something like a home-brew fermenting bucket already fitted with a tap. An upturned plastic garden sieve would probably do the job as a drainage grid. Whatever you use, bear in mind it has to be retrieved from the gunk in the bucket each time it’s emptied, and it needs to be easily cleaned!
An alternative version uses two tightly nesting buckets. Drill 20 to 30 small holes in the base of the inside bucket so liquid can drain through into the bottom bucket. Place a tight-fitting lid on the top bucket. This system has no tap, but the top bucket can be lifted off and any liquid collected in the bottom bucket can be poured off into a separate container.