Wednesday, March 3, 2010

I love bokashi

As I wasn't really in a position to create and maintain a standard compost bin/heap and as I had access to a reasonable quanity of food scraps, including material not suited to standard compost, I thought I'd have a look at bokashi (I already had a worm farm).

Admitedly, I balked at the cost of the commercially available starter bin+mix packs and wondered whether it'd really be that much better than just digging a hole and burying the scraps in the ground. But, in the end I thought it'd only be in use if it worked, so parted with what I felt was a large sum of money for what was a small plastic container with a tap and a small bag of the mix. It was a start.

Getting to the point, fast forwarding twelve month - it's brilliant. It's helped turn my wormless garden bed of clay (which required a crowbar and mattock to start) into a thriving worm metropolis which is a joy to plant. Material decomposes into the soil much, much faster than buried material without bokashi. Corn husks have broken down to nearly nothing in as little as three weeks with bokashi, whereas they're still almost whole some two months later if simply buried.

I was hooked on the result, but still couldn't face the expense of the packs of bokashi mix and I needed more bins. I filled the bin in four days and then had to wait two weeks until I could empty it. I thought I'd DIY both the additional buckets I needed as well as the grain mix.

DIY Bokashi Bin
Materials used
  • A 20 litre handy pail - basically a 20 litre bucket with a tight fitting lid
  • A tap (optional). I set the tap as close to the bottom of the pail as possible. Cut off any extra piping from the tap to aid with the flow of the juice.  If you don't intend to syphon off the juice as it ferments then the tap is entirely optional - my latest bucket doesn't have the tap
  • A plastic microwave dish with several holes drilled into it - it should fit snuggly just off the bottom of the pail.  This separates the solids from the liquid - the microwave lids I use provide about a 2->3cm gap between the bottom of the bucket and bottom of the food scraps..
  • A garbage bag to cover the scraps as you add them.
Total cost was about $20 per bucket with tap. The water filter tap I used was a significant portion of the cost so a cheaper tap would decrease the cost.  Of course if you don't plan to use the juice then you don't need the tap at all.

Bokashi Mix
Ingredients (I remember the ratio 1:1:100:150)
  • 30 ml of molasses
  • 30 ml of EM (Commercial product of Effective Microorganisms - primarily lactobacillus bacteria)
  • 3 litres of quite warm water
  • 4.5kg of wheat bran
  • a jug/bucket which'll hold 3+ litres
  • a plastic ladle/spoon for stiring the liquid mix
  • a large air-tight container, such as a plastic storage container with a lid
  • a tarp for drying resultant bokashi grain mix
  • Mix the quite warm water, molasses and EM in the plastic jug
  • Pour the liquid mixture over the bran
  • Mix the bran and the liquid until the bran is moistened evenly (break apart any large lumps of bran).
  • Put the mixture in the air-tight container. Squash it down to remove as much air as possible. I usually fill the remaining space with some lengths of scrap plastic - it also helps with the air-tight seal as the container I use has a clip on lid.
  • Leave it for about a month in a warm place. (normal room temperature). The surface of the mixture should become covered with a white mold.
  • When it's done, spread the mixture out on a tarp, away from direct sunlight and moisture and leave until it's completely dry. Break up any lumps. I'd also recommend drying it out of reach of the cat. I left my very first mix for a minute and the cat snuck in to add its own special ingredient, clearly thinking I'd created the largest cat litter tray in all of history.
  • Pack into large ziplock bags and store until needed.
Useful links:
My bokashi efforts were guided heavily by information presented in the two links below:


  1. Never heard of bokashi. Interesting stuff! :D

  2. What's EM?

    Sorry if this is a foolish question.