Bokashi bin, food wasteBokashi is the Japanese word for fermented organic matter.

A bokashi bin or bucket is a practical and convenient way to transform your kitchen waste into nutrient-rich compost for your garden.

It is a unique recycling system that ferments food waste in a sealed, air-tight container. Commercial bokashi buckets can be purchased through selected distributers, or you can make your own.

Fermenting waste

The bokashi process works by fermenting organic waste rather than composting. Compost bins and worm farms work differently and these cannot take things like meat, dairy, citrus and bread, where a bokashi bucket can take almost any food waste.

The secret to the process is the bokashi grain added after each layer of food waste. This grain contains beneficial micro-organisms that act to ferment or pickle the food waste. Bokashi grain can be purchased commercially but it is possible to make your own if you have the right ingredients. You can also get a bokashi spray that contains the same effective micro-organisms.

What can go in a bokashi bin

You can add almost any kitchen food waste, including:

  • All fruit and vegetable scraps
  • Processed foods
  • Cheese and solid dairy products
  • Cooked and uncooked meat, including fish and other seafood
  • Bread, cake and biscuits
  • Tea bags and coffee grounds
  • Pasta and rice.

What not to add

  • Liquids such as milk, fruit juice or water
  • Large bones
  • Foods that are rotted or mouldy
  • Foods contaminated by chemicals
  • Dog and cat excrement
  • Packaging materials such as foil or plastic wrap.

How to use your bokashi bin

Step 1: Add a generous handful of bokashi grain to the bottom of the bucket.

Step 2: Cut or mash your kitchen scraps into small pieces and place into the bucket. This will speed up the fermentation process.

Step 3: Add a handful of bokashi grain, or enough to evenly cover the previous layer of food scraps. Repeat this for every layer of food waste you add to the bucket.

Step 4: Push down contents to remove any air pockets and ensure the lid is on tight.

Step 5: When the bucket is full, top off with a generous layer of Bokashi grain and leave in a cool, dark place for a week, before burying somewhere in your garden (minimum 30cm deep). You may also empty the nutrient-rich contents straight into a compost bin or bury immediately, where it will continue to breakdown.

Using your Bokashi juice

Bokashi juice contains nutrients from the food waste and is alive with effective micro-organisms. This makes a terrific fertiliser. To fertilise an existing garden or pot plants use 1 teaspoon to 2-3 litres of water and apply directly to the soil. For trees and shrubs use 2 teaspoons to 2-3 litres of water. Do not apply directly to foliage, as this may burn your plants.

Bokashi juice cannot be stored and must be used within 24 hours after draining from the bucket. If you don’t want to use it all on the garden, try pouring the concentrated bokashi juice down the kitchen/bathroom drains and toilets to help control odour and algae build-up.

Helpful tips

  • You cannot add too much Bokashi grain
  • Always close the lid tightly and drain the bokashi juice frequently
  • When burying the contents from a full bokashi bin, try covering the freshly dug hole with something stable and heavy to prevent animals from digging it up
  • The more times you add food waste to your bokashi bin, the more grain you will use. Try storing your food scraps in the fridge and add them to your bin on a weekly basis
  • Bokashi compost is acidic when first dug in, but neutralises after 7-10 days. Avoid burying the compost close to other plants and wait at least 2 weeks before planting any new plants.

How to make your own bokashi bin

What you’ll need:

  • 2 x 20L identical containers with lids
  • Drill
  • Tap (optional)
  • Old flyscreen
  • Bokashi grain or spray.

Step 1: Find two containers with lids (20L Handy pails work well)

Step 2: Get one container and drill a series of small holes in the bottom

Step 3: Place the bucket with the drill holes inside the other. Cut a round piece of flyscreen and attach to the bottom of the bucket above the drill holes (remember to keep a lid for the top container)

The containers need to be identical so that they are able to fit perfectly inside each other and air-tight.

Step 4: You may install a tap at the base of the bottom bucket to extract the Bokashi juice, or alternatively you can simply lift the top bucket out and pour out the juice into a smaller container or bucket. Dilute (1 teaspoon of juice with 2-3L of water) and use on your garden or put down your drains.