Quick Guide to Bokashi Composting

Composting is a process of decomposition of organic materials which breaks down into a dark brown crumbly "earthy" substance that can be used to supplement and provide rich nutrients to soil.  Some useful items that can be composted such as leftovers or vegetable scraps, which usually goes into the trash can could be diverted to supplement the backyard garden.  Certain states such as California and many cities are now requiring that organic waste be placed in different bins to help with reducing waste.  There are plenty types of composting:

• Backyard composting
• Vermicomposting (worm composting)
• Bokashi composting

In this post we'll be focusing on the Bokashi style of composting.

What is Bokashi Composting?

Bokashi composting is a type of anaerobic fermentation, which uses a lack or reduced amount of oxygen, using a specific mix of beneficial microorganisms to break down food waste into nutrient rich compost and liquid by-product that can be used to fertilize plants.  This type of composting originated in Japan, but is used around the world.  Bokashi composting is a great way to reduce food waste and improve soil health.  It is also a relatively easy process that can be done in a small spaces (corner of the kitchen, under the sink, balcony, etc.). And because of the air tight nature of the process odors are not leaked out into the environment.

What can you compost with Bokashi?

In bokashi composting many types of food and other organic material can be used such as kitchen scraps, fruit and vegetable peels, coffee grounds, tea leaves, and even items that are not typically acceptable in other composting methods such as meat, dairy, egg shells, cooked food, tea bags, coffee filters, and more.  To ensure that the organisms have the most amount of space to grow and more surface area to compost, it is helpful to process the food products into a food processor or blender before putting it into the bokashi bucket.  However, if food is starting to get spoiled and there is mold growth on the food, it's better to throw that out so the bokashi bucket does not get overrun with mold.

Getting Started With Bokashi - Things Needed

To start, there are only 2 things that are needed - a bucket and the microorganisms.  An air tight bucket is a required for this composting process to create an anaerobic (lack of oxygen) condition. There are a also a few products commercially available to introduce the necessary microorganisms to break down the compost -  Bokashi Bran and a Bokashi spray.

How To Compost With Bokashi

With the SCD bokashi bucket product there is a filter that mostly keeps the organic material away from the spigot, but if there is no filter available keep some compostable material that has a more rigid structure like cardboard or egg shells that can prevent the spigot from getting blocked by smaller material such as the bokashi bran.

Once a protective filter is placed, the organic material can be added.  Organic material can be continuously added until the bucket is full.  After 1 inch of organic material is placed into the bucket sprinkle a handful of bokashi bran on top.  Alternatively, after every time organic material is introduced into the bokashi bucket, spray some of the bokashi spray over the material.  Repeat layering organic material and sprinkling bokashi bran/bokashi spray in 1 inch layers until the bucket is full.  Put the lid back on to create the closed off anaerobic condition. It is not necessary to add water since the moisture will come from the food scraps and other organic material added to the bin.

For this method of composting, it's beneficial to help break down the organic material prior to putting it into the bin so that there's more surface area for the bacteria and other microorganisms to process and to really let it get everywhere and in between the rest of the food material.  Although this is optional, I want to make sure the microorganisms have a chance to get through to all the material and break it all down.  To do this I got a food processor or chopper, even a blender would do.  I would throw everything in to fit like plant stems and leaves, leftover french fries, whole mushy fruits, egg shells.  Then pulse the power a few times and then dump the material into the bin.

It may take some time for the bucket to fill up.  During this time oxygen is being exposed to the bokashi bucket.  To help the microorganisms to grow in anaerobic conditions (lack of oxygen), it is helpful to place a barrier such as a piece of cardboard or a plastic trash bag on top of the compost until the bucket is full.  This anaerobic condition allows the beneficial microorganisms to breaking the organic material down producing a fermented byproduct. The fermentation process does not produce a foul or rotten odors as it does in traditional composting.

When one bucket is finished, it can be transferred to a composting bin, or allowed to continue on to ferment and compost further and pull off more bokashi tea.

What Should the Compost Look Like In Progress?

During the bokashi composting process, organisms will grow and multiply.  Seeing a white filamentous growth is good.  Different colors are good - green, blue, white. 

However, a dark green, black, or brown filamentous growth is mold, and if it over running the entire bokashi bucket it's best to throw away the batch do a thorough cleaning, and start fresh.  

How Long Does it Take Until the Bokashi Compost is Ready?

The bokashi composting process typically takes around two weeks to a month, depending on the ambient temperature. In hotter environments or when the bucket is exposed to the sun, the microorganisms can multiply easier, but in colder environments it may take longer for the bacteria to grow and ferment.  During the fermentation time period, it is essential to drain the liquid that accumulates in the container. This liquid, known as "bokashi tea," is rich in nutrients and can be diluted and used as a liquid fertilizer.

For us, two people and cooking regularly, it takes about a week or two to fill up.  We have two buckets so that while one bucket is full undergoing the fermentation process and producing tea, we are filling up the other bucket.  Then when one is full

Using the resulting Bokashi Compost & Tea

Once the bokashi composting process is complete, the fermented waste is can buried in the soil, usually 6 inches deep and then covered back up with soil, or added to a traditional compost pile where it can break down further and introduce the microorganism to the compost environment. Over time, the fermented compost waste breaks down further, contributing to the overall soil health and fertility.

The bokashi tea liquid can be diluted with water and poured on plants or added to your compost pile to add healthy organism and nutrients to the soil.  Caution when placing tea directly onto plants as the tea is acidic in nature, which depending on the plant, may not take very well.

Cleaning the Bokashi Bucket

After the finish compost is removed, the bucket needs to be cleaned out before adding another set of compost.  Theoretically all the good bacteria, fungi, and yeast will still be present on the container, but there may also be some mold present. It is better to ensure that the bucket is completely free of mold. I typically use a Clorox spray which has bleach to ensure that any mold is killed.  I spray the bucket, lid, and filter, and then leave them sitting for 10 minutes.  Afterwards rinse the bucket out.  Follow the instructions of the cleaning product and be sure to test it out to see if it's compatible with the bucket.

Conclusion

Bokashi composting is an easy way to reduce organic waste and can easily be done in small environments.  The fermented compost and tea are beneficial to the soil and can easily add nutrients to soil for other plants.  Good luck on your bokashi composting adventures!  Leave a comment on how you're doing or if you need any help with your process.