Everything You Need To Know About Bokashi Composting

Bokashi is a fermentation process where organic waste is broken down using an inoculant of beneficial microorganisms. The process works without oxygen (anaerobic decomposition).

Bokashi is an ideal solution for recycling food waste for homes, restaurants & offices constrained in space. But also more extensive facilities with lots of food waste. This is because you can recycle most of your organic waste, including cooked food, meat and dairy, without worrying about foul smells or attracting animals.

Materials Needed

1) Inoculated Bran.

This can be wheat bran, rice bran or sawdust inoculated with naturally occurring microbes known as EM (effective microbes)

2) 2 Buckets – one should have a lid (this can be any size of bucket) OR 1 Bucket with a tap. The amount of waste you produce could determine the size of the bucket to use. You just need to ensure that your bucket size will not require you to keep opening it to top up. So as an example, a household with 4 – 5 people can fill up a 20KG bucket in about a month. 

3) 1 piece of cotton cloth (dish cloth or an old T-shirt) – only applicable if using 2 buckets (this will act as a solid waste filter)

4) 1 stone or piece of wood – only applicable if using 2 buckets

5) Cotton Cloth or Old Tshirt or Garbage Bin Liner (this will be used to compress and push out any air from the top of the bin)

What To Bokashi

All Vegetable and Fruit Waste

Crushed Egg Shells

Shredded Newspaper

Shredded Carton/Cardboard Boxes (remove all pins and tapes)

Shredded Paper

Serviettes

Coffee and Tea leaves

Toilet paper Roll

Plant matter (make sure they are not diseased)

Firewood Ash

Animal Manure (Horse, Cow, Chicken, Goat, Rabbits)

Human Hair

Grass

Wood Chips

Houseplants

Cooked Food

Meat Bones

Dairy Products

Oily Food and Tissues

What NOT to Bokashi

Rotten / Mouldy food items as the organisms or pathogens in the mould can outcompete the beneficial microbes.

Procedure

BUCKET WITH DRAINAGE HOLES AT THE BOTTOM

Step 1: Put some holes at the bottom of one of the buckets (if using a bucket with a tap, skip to Step 5, and if using a bucket without drainage, skip to Step 6)

• It should be enough to allow filtration of excess liquid

Step 2: Put the cloth or old t-shirt at the bottom of the bucket with holes

• This is to filter excess liquid and retain the waste

Step 3: Put the stone/block at the bottom of the bucket without holes

Step 4: Put the bucket with holes inside the bucket holes

• To make it clear, the bucket without holes is at the bottom, and then the bucket with holes is placed inside it and sits on top of the stone/piece of wood. So at this point, you now have 2 buckets in one. The one with holes is the one at the top where you will put your waste. Proceed to Step 5

If you are using a bucket with a tap, this is where you start.

Step 5: Sprinkle some inoculated bran at the bottom of your bucket and proceed to Step 7

If you use a bucket without drainage, this is where you start.

Step 6: Sprinkle some inoculated bran at the bottom of the bucket and put a layer of dry shredded paper, cardboard box or dry sawdust. Proceed to Step 7

Step 7: Put your food waste inside the bucket.

• Important Note: It is advisable but not mandatory to chop the waste into small sizes for faster fermentation.

Step 8: Add a layer of the inoculated bran and press it down with the cloth or garbage bin liner. The bran should not be too much, just enough to cover the food with a thin layer.

• The action of compressing the waste helps to remove any air spaces between the materials and also pushes excess liquid to the bottom.

Using a garbage bag liner to compress the waste and push air out

Step 9: Cover the bucket and make sure it is completely airtight. 

Step 10: If the bucket is not full, you can keep adding your food waste. However, to avoid opening the bucket too many times, we recommend having a temporary bin and then adding the food waste into the Bokashi bin once a week. Make sure to add a layer of inoculated bran after adding food waste and press it down to release any trapped air inside the waste.

Step 11: Once the bucket is full, put it aside to sit for 15 days without opening. At this point, you can start another Bokashi bin using the steps described above. Store the full bucket away from full sunlight, following step 12.

Step 12: Bokashi Tea 

Food waste contains liquid that must be drained often to avoid a soggy bin that can result in rotting. If you use a bucket without drainage, the liquid will be absorbed by the dry matter you put at the bottom.

The liquid is known as Bokashi Tea and contains beneficial nutrients for your plants. The liquid, however, is highly acidic, so you should dilute it at a ratio of 10ML per 1Litre of water. You can use it to spray your plants or drench the soil. The liquid can also be stored in a sealed container and used as needed.

Fermented Waste After 15 Days

15 Days have passed, and the microbes in the Bokashi bin have been hard at work fermenting the foodstuff. Bokashi does not result in a finished product; instead, it produces a pre-compost. This means that you will need to go a step further to ‘finish’ the Compost before you can add it to your plants.

There are a few things to note about your fermented waste:-

1) Some food items will only slightly change in appearance. As you can see in this image, you probably could identify some things. This is unlike composting, which results in a dark earth-smelling product.

2) The fermented waste has a sour vinegar-like smell. This is a different smell from rotten food.

3) A white cotton-like mycelium may form at the top of your fermented waste. This is typically a good sign that the fermentation has been successful. This is, however, not a mandatory sign of success. If your fermented waste does not have the mycelium, that is OK too. You may also see a bluish-green-like mould which is also OK as long as it does not smell rotten.

Fermented Waste With Mycelium and Without Mycelium

What To Do With The Fermented Waste

As mentioned before, Bokashi is a pre-composting process. This means that you need to take some additional steps before you can use it. After the fermentation cycle, it is time to finish the process. There are several options for doing this.

Option 1: Incorporate it into your Garden Soil

This method is known as Trench Method and applies if you have garden/farm space to dig a trench and incorporate it into the soil.

Procedure: 

Dig a trench of about 12 inches in depth or so. This is just for guidance, and the size does not really matter. This trench should be in an area where you plan on planting. If you have raised garden beds, you can dig a trench inside the garden beds.

Once you have dug the trench, empty the fermented waste and spread it evenly across the trench.

Add about an inch of soil to the fermented waste and mix it thoroughly.

Backfill the trench and make sure the waste is completely buried.

You can proceed and plant from about 2 weeks after burying this pre-post. The soil micro and macro flora will work on assimilating the pre-compost into the soil and help build the soil biology.

The fermented bokashi is a beautiful soil amendment because of its beneficial microbes. So you can rotate the trenches in different parts of the garden and use them to build your soils over time.

FAQs about this procedure

1) Isn’t Bokashi very acidic? Thus making the soil acidic?

The answer to this is yes. But the soil web neutralizes this acidity within about 2 – 3 weeks of burying the pre-compost into the ground.

2) Does burying this pre-compost attract animals?

Dogs do tend to dig up buried Bokashi. So you can choose to bury it deep enough to mitigate this.

3) What if the garden is already planted?

You can dig the trenches or holes around the plants (check not to disturb the roots of the plants as this will damage them), add the pre-compost, mix thoroughly with soil and cover the hole.

Option 2: Compost it in a bucket (Soil Factory Method)

Another way of finishing your pre-compost is to compost it in a bucket, referred to as a soil factory. This option works for small spaces, container gardeners, or if you do not want to add it to your garden.

Bokashi Pre-Compost in Final Composting Stage

For this option, you will need about half a bucket of dry Compost or garden soil.

Procedure

Step 1: Drill holes around the top sides of the bucket and the bottom to drain any excess liquids that may collect in the. If you have some garden space and can place the bucket in the garden, you can also drill holes at the bottom of the bucket. This will allow oxygen circulation, a critical requirement for composting (aerobic).

Step 2: Put dry Compost or dry garden soil up to 1/3rd of the bucket. Add the fermented bokashi until the bucket is about 2/3rds full, and mix thoroughly. Do not worry too much if your fermented bokashi is less in quantity. This is just a guide. It is important to note that the fermented bokashi should not be dripping wet. You should drain the liquid as much as possible to avoid foul odour and insects coming to your bin. The mixture of the bokashi and the dry Compost or dry garden soil should feel damp like a wrung-out sponge and not wet. If it is wet, add more dry Compost or dry garden soil.

Step 3: Add the rest of the dry Compost or dry garden soil and press it down to remove any large air gaps and to cover the fermented bokashi. Do not mix it.

Step 4: Cover the bucket and let it sit for 4 weeks. The fermented waste will continue to break down until it becomes soil. Remember, it is a best practice to chop your waste into small pieces and crush egg shells so that the fermentation and composting process can work faster. If you put big materials, you will see that they take longer to break down.

Step 5: After about 4 or 5 weeks, the fermented bokashi should be fully composted and ready for use. You can now incorporate into your garden as topsoil, use it for potting your houseplants, use it to start seeds, or you can store it for use at a later stage.

FAQs about this procedure

1) What is the soil factory’s ratio for soil to fermented bokashi?

The ideal ratio is 1 part fermented Bokashi to 2 parts soil (or Compost)

2) Can I add the fermented bokashi into an outdoor composting bin?

Yes, you can. However, you will lose some advantages of the fermentation system, such as some of the bacteria, enzymes, and nutrients will be lost

3) Do I have to keep getting compost or garden soil for my Bokashi bins?

No, you can save some for the subsequent fermentation round and keep saving as you go along

4) What do I do with the excess finished bokashi Compost?

You can store it in a bucket, sack or carton box and use it at your leisure as it does not go bad. You can also donate it to neighbours, the local school or the community as our soils need the support.

Troubleshooting The Bokashi Fermentation Process

Your Bokashi set-up may run into problems at different stages. Here are a few examples of common issues and how to resolve them.

During Waste Fermentation Phase – First 15 days from setting up the bin

1) Smelly Bin When Closed

A Bokashi bin should not produce any odour when sealed at all. So if there is a smell, it means that it is not closed correctly, or perhaps there is a hole somewhere in the bin allowing air to enter and come out.

Bokashi is an anaerobic fermentation process. If oxygen is allowed in, the waste will rot and smell instead of fermenting.

If you are in this situation, open the bin and establish the extent of the rot. If mould has started forming inside the bokashi bin, it is advisable to throw away the waste. If you have a backyard compost bin, you can introduce this rotten waste very little at a time and thoroughly mixed in the bokashi bin to avoid foul smells and prevent the outdoor Compost from getting too wet. Another solution is to dig trenches in the garden, add this rotten bokashi, sprinkle inoculated bran and backfill with soil. After about 1 – 1.5 months, the soil food web will have worked on the rotten bokashi, and foul odours will be gone. You can then plant as needed.

2) Smelly When Opened

As mentioned earlier, when you open your Bokashi bin to top up or at the end of the fermentation process, it should produce a sour vinegar-like odour. Some people do not like it. However, it should not smell rotten (there is a distinct difference). If it has a rancid odour, it means some air was trapped inside.

If you are in this situation, open the bin and establish the extent of the rot. If mould has started forming inside the bokashi bin, it is advisable to throw away the waste. If you have a backyard compost bin, you can introduce this rotten waste very little at a time and thoroughly mixed in the bokashi bin to avoid foul smells and prevent the outdoor Compost from getting too wet.

3) No liquid

If you are using a drainage bin and notice there is hardly any liquid or none at all, there is no reason to panic. Everything is fine.

4) Too much liquid

If you are topping up your bin and notice that the contents are soggy, drain as much liquid as possible and add dry matter, such as a shredded cardboard box or newspaper or wood chips that can absorb the liquid. You can also add a thicker layer of the bran. Remember to compress it to remove any air pockets and seal it tightly.

5) White or Bluish cotton-like substance at the top

This is known as mycelium and is a good sign that your Bokashi is fermenting as it should.

Conclusion

Bokashi fermentation is a convenient and easy way of composting your waste at home. It is also an excellent method that can complement worm composting. You can use vermicompost to finish the bokashi making a rich nutritious product for your plants and garden.