DIY Bokashi bin

Worms can be a little picky about what they eat, so to make sure I compost as much as possible, I put the food scraps the worms won’t eat into a Bokashi bin.


Bokashi is an anaerobic (oxygen-free) fermenting composting systems. Specific microorganisms effectively pickle the food scraps. If done correctly the compost should not smell, and is a good fit for small apartments.

All kitchen waste can be put in a Bokashi, (which is a huge benefit over worm farms or traditional composting), although it’s best to avoid large bones, paper, and excessive amounts of liquid.

An expensive way to compost

The only drawback to the Bokashi system, is that it’s expensive:

  • a properly designed 20L Bokashi bin costs around $75-100 AUD and you’ll need at least two of these for a small family (3 people). They fill up quickly, and it’s best to have three or four.
  • additionally it requires an expensive mix of active ingredients. Typically you use 1 tablespoon of Bokashi mix for every cup of waste, and more for high protein foods (such as meat, fish, cheese and eggs). For an 8-10 cup scrap bin, you need ½ cup (or more) of Bokashi mix. 1kg of Bokashi mix costs about $10 AUD, so you’re using probably a bag of Bokashi mix every month in a small household, more if you’re primarily using it for meat and dairy (like I am).

The expense is the reason that I primarily use worm farms to process most of my kitchen waste, and put only the things that worms can’t eat in the Bokashi.

The second reason Bokashi is my fallback option, is that unless you follow the proportions of Bokashi mix to the letter, then your Bokashi bin will be super stinky! It’s an unpleasant pickled poo smell, not nearly as disgusting as actual poo, but not nice (and flies loooove it). Everyone I’ve ever known who had a Bokashi never followed the instructions (we’re all cheapskates and skimp on the mix), but if you can put up with the stink (it’s only when you open the lid) then you’ll be fine.

Cheat’s Bokashi

diy-bokashiMy Bokashi has always been stinky. So I figured that I would just live with it, and use this super cheat’s version of a bokashi bin. It’s not air-tight, so it won’t undergo anaerobic fermentation, but it’s no stinkier than my old Bokashi bin, and of course it’s heaps cheaper.

My system uses natural yeast fermentation, and I discovered it when I fed my Bokashi with sourdough starter and it was the happiest it’s ever been.

  1. Find 2 suitable containers. You guessed it, two 50-60L plastic garbage bins with secure lids are perfect.
  2. Buy one bag of Bokashi mix per bin. You can buy these at some hardware stores (definitely Bunnings), sustainable supply places, or online.
  3. Drill 4x 5mm holes in the base of the bin. These are for drainage, but you don’t want them to be too efficient.
  4. Place the container in a shaded area (under a deciduous tree is perfect, shade in summer, sun in winter). If you place the bin under trees, you might like to placing a piece of carpet underneath to stop tree roots from invading the bin. But you don’t want the bin to drain too quickly (as the liquid is necessary for fermentation)
  5. Place your Bokashi scraps in the bin then sprinkle a handful of the mix over the scraps. Pour water over the scraps until they are mostly covered. Using an old potato masher or thick stump of wood, push all the scraps so they are submerged.
  6. If you have sourdough starter, just pour this into the bokashi bin and mix around.
  7. When you see natural yeasts/moulds on the citrus, stir these into the mix, this will accelerate the fermentation process.
  8. When the bin is full, start on your second bin and let the first one ferment for 3 months or so. Typically it takes a family of 3, about 6 months to fill the bin (if their primary composting is a worm farm). Every time you start a new bokashi, you’ll need to buy the bokashi mix.

Cheat’s Bokashi is not for the faint-hearted or fragrance challenged, but if you want to use all of your scraps and keep as much out of landfill as possible, then a bit of stink every three months is probably worth it.

Bokashi and Hugelkultur

When fermentation is complete (takes about 2-3 months), you will need to bury your Bokashi compost in the garden to complete the process. This makes it ideal for your hugel building! And did I mention that worms love it too? Yay!

Pile it on top of your hugel-in-progress, then immediately put woodchips, grass clippings or compost on it (because the smell will attract every fly in the area and make your neighbours wonder what’s just died in your garden), then cover with 20cm of growing medium. The faster you can do this, the less stink, so get organised and prepare everything before you start.

You can’t plant directly into the Bokashi compost, but as your mound breaks down, your initial fertiliser runs out and the roots of your plants go deeper, they will be fed by the decomposted bokashi compost. Worms will also move the bokashi compost around your mound.

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