How To Add Bokashi To Compost: Bins, Tumblers, And Worm Bins

Recently filled up your bokashi bin and figuring out what to do with your bokashi pre-compost?

If you’re considering adding bokashi pre-compost to your current composting setup, this article is for you.

I cover:

Ready? Let’s jump right in.

How do you add bokashi to a compost bin? It’s best to add bokashi to an established compost bin that’s full of life. Adding in a handful of garden soil will help to introduce the beneficial soil microbes that break down bokashi pre-compost. Bokashi is full of nitrogen, so it’s important to add enough carbon-rich materials to balance this.

How to add bokashi to compost

You can process your fermented food waste in a compost bin instead of burying it

Bokashi can be paired with composting to speed up the overall decomposition process. But there are a few watch outs.

A major one is to avoid starting a compost bin with bokashi. 

Get the bin working with normal food waste, then add the bokashi.

Bokashi needs your compost to be full of microbial life in order to successfully break the fermented waste. 

If you add the bokashi to a bin that’s void of life (either because the bin hasn’t been established yet or because the compost inside has been left to dry out) then instead of breaking down you risk it becoming anaerobic and starting to stink.

You also need sufficient mass to be able to mix your bokashi in with the other materials. Your bokashi pre compost should not make up the majority of your compost or it may clump.

To add bokashi to compost:

  1. First, make sure your bin is in good health. Turn your compost pile to aerate it and check the moisture levels in your bin. 
  2. Open your bokashi waste bin and empty the contents into a second container
  3. Break the bokashi waste up with your hands. This helps to make sure the bokashi doesn’t clump together too much in your compost
  4. Add the bokashi pre compost to your compost bin or pile, bury it near to the middle of your pile just like you would do with normal food waste. Try to mix it around a bit with the other waste in your bin to fully incorporate it.
  5. Add a handful of garden soil (very important for an enclosed bin that doesn’t rest on soil).
  6. Add in extra brown materials like dried leaves or cardboard to keep the carbon:nitrogen ratio in check.  Bokashi requires quite a lot of carbon to balance the nitrogen content, so don’t skimp on the browns!
  7. Cover the bokashi waste and continue to compost as normal.

The garden soil is important because bokashi is mainly broken down by microbes that live in soil. That’s why it does so well when you bury it. Adding a handful of soil will ensure these microbes are present.

Completely enclosed compost bins (right) have no natural way to get soil microbes

In an open pile (or one that rests on the ground), the soil microbes can find their way in. But in a closed system, you need to add them manually.

If you have no choice but to put your bokashi in an empty compost bin, make sure to add in plenty of garden soil or old compost along with it. This will help to introduce the necessary microbial life. 

The bokashi waste should break down relatively quickly. It’s already teeming with microbes that are breaking it down, and these microbes will help boost the overall performance of your compost bin. 

You may notice a foul smell for the first day or so. This should disappear after 2-3 days. The most common cause of smells is not adding enough bokashi bran to cover your food scraps. If you experience any smells, make sure to add more bran the next time around.

If the smell continues it’s likely due to the bokashi pre-compost turning anaerobic.

This could be because it’s become too compacted, or you may not have added enough brown material along with the bokashi.

To fix it, give the compost a big turn and make sure there are no clumps of bokashi pre compost. If you notice any clumps, break them apart. 

Big clumps of bokashi can easily turn anaerobic because it’s hard for the microbes/air to penetrate the clump. This causes the middle of the clump to become starved of oxygen.

If the pile is too soggy, add some more brown materials in to help soak up the excess moisture.

How to add bokashi to a compost tumbler

Compost tumblers are raised off the ground

As with any compost pile, it’s best to add bokashi to an already established compost tumbler because the bokashi needs an abundance of microbial life to break it down. It’s also very important to add a handful of garden soil to the tumbler to introduce essential soil microbes.

Bokashi relies on soil microbes to break it down. This is a problem for compost tumblers because the compost inside doesn’t sit on the soil. 

Thankfully, it’s an easy problem to solve.

Adding a few handfuls of healthy garden soil into the tumbler along with the bokashi will introduce the essential microbes to the bin. As they feed on the bokashi, the microbe population will flourish.

Compost tumblers are typically easier to manage than compost bins, but they’re also more prone to smells. Having a smaller space to compost in means you have less room for mistakes.

You also have the potential problem of compost balls in tumblers. 

Wet materials can form solid balls in a compost tumbler

The rotating action can sometimes cause wetter materials in the bin to stick together and turn into big balls of compacted material.

Bokashi pre-compost is exactly the type of material that would be affected by this.

And the balls of bokashi will quickly turn anaerobic and start to smell.

Making sure the bokashi is well broken up before you put it in the bin can help, but a foolproof method to prevent this is to add some sticks into the bin.

The sticks will help keep the material in your bin separated and well aerated. Wood chips also work well.

When it comes to bokashi, I suggest starting small. Add a portion of your bokashi to the tumbler and see how it breaks down. It shouldn’t take long, and once it’s nearly decomposed you can add more. 

Once you become confident that your compost tumbler is dealing well with the bokashi well, you can increase the amount you add.

How to add bokashi to a worm bin

Composting worms will devour bokashi pre-compost as soon as they get used to it. Keep in mind that bokashi is acidic, so to keep the worm’s environment neutral, it’s best to add in something alkaline along with the bokashi. Crushed eggshells are perfect for this. 

Adding bokashi to a worm bin is one of the fastest ways to process it.

Worms actually feed more on the microbes that are breaking down the food than the food itself.

When you put normal waste in a worm bin, you have to wait for the microbes to move in and start processing it before the worms will go near it.

But bokashi pre-compost is already teaming with microbes, so the worms can start working on it as soon as it goes in.

Sounds great, right?

Worms like to live in a neutral environment, and boksahi pre-compost is acidic

There’s one small issue, and that’s the acidity of the bokashi.

Bokashi pre-compost has a pH of around 3-4. Worms prefer to work in a neutral environment with a pH of around 6-7.

Initially, the acidity might put the worms off, but if you start with a very small amount of the bokashi they’ll be fine.

As they get more and more used to bokashi, you can increase the amount you feed them.

If you feed your worms a lot of bokashi, the entire bin will start becoming more acidic. The worms might tolerate eating acidic things, but they won’t like it when their bedding starts to drop in pH.

To counteract this you can add something alkaline alongside the bokashi. Crushed egg shells or garden lime (not the fruit!) are perfect. 

Some people even mix their bokashi pre-compost with lime before adding it into the bin the neutralize the pH. 

Small white worms (pot worms) are a sign of an acidic environment

Pot worms are an early sign that your bin is becoming too acidic. If you notice the population of these small white worms rise, start adding more eggshells in to lower the pH. 

Can you add bokashi tea to compost?

You can use bokashi tea undiluted as a compost accelerator (picture source)

Fresh bokashi tea is a great addition to a compost pile. 

It’s full of beneficial microbes that will help accelerate decomposition in your pile. You can pour the bokashi tea straight onto the compost pile without diluting it. That said, if your pile is looking a little dry, you can dilute the tea to get more liquid.

Make sure to use fresh bokashi tea. Bokashi tea doesn’t last long at all and will start to go off within a few hours of harvesting it. You’ll be able to tell if the tea has gone off by the smell. It will start to smell foul and putrid.

Also, keep an eye on the moisture levels in your bin and stop adding the tea if your bin starts to get too wet. If you’re worried about this, you can always add some extra dry materials into your bin when you add the bokashi tea. Cardboard is good at soaking up moisture.

You can also use the bokashi tea to water your plants or to get rid of funky smells in your drains.

Adding bokashi bran into compost 

Bokashi bran has multiple uses. The main one is to ferment food waste, but it also makes an excellent compost accelerator. 

You can add bokashi bran straight into your compost pile (source: Al Pasternak)

If your compost is struggling, a handful of bokashi bran could be the kickstart it needs. Add the bokashi bran into the middle of the pile and cover it. Don’t turn the compost for 4-5 days after adding the bran.

Bokashi bran is full of beneficial microbes that can work on the food and garden waste in your compost. Adding these microbes into your pile will help get more life into the pile and therefore speed up decomposition.

If you look closely, you should be able to see some fungal or hyphae growth appear after you add the bran. This is a sign that it’s working and your pile is once again starting to thrive.

Since bokashi bran is anaerobic it’s very important that you completely cover the bran when you first add it and then avoid turning the compost. You want to prevent any air from getting to the bran. 

After 4-5 days the bran should have had enough time to multiply throughout the pile and start activating.

Making a fungal mat

A second, less common way of adding bokashi into compost is to make a fungal mat with it and then add the fungal mat into the compost.

To make a fungal mat. get a shallow tray and line it with moist soil. Add a layer of bokashi bran on top and then cover it with plastic. Leave it for 4-5 days.

When you come back, the tray should be covered in a thick layer of fungal growth. You can add this into your compost to help make it more fungally dominated. 

Fungally dominated compost is great for berries. 

Using bokashi bran in compost tea

Compost tea can benefit massively from a spoonful of bokashi bran (source: Suzie’s Farm)

You can also add bokashi bran into your compost tea. Simply add a spoonful of the bran into your normal tea bag mix. The bokashi will add LOTS of extra beneficial microbes into the mixture. 

Adding bokashi bran will speed up the brewing time, sometimes meaning your tea will be ready 6 hours earlier than normal! So if you’ve added some bran make sure to check on your tea earlier than normal.