The Bokashi composting method is a way to recycle food waste that depends on fermentation to retain optimal nutritional value. The final bokashi product can be added back to your garden as a soil amendment or to your traditional compost pile as an accelerant.
It’s a somewhat controversial method of composting (as controversial as composting gets) because it’s not composting in the traditional sense.
This guide explains the science of the method and it also walks you through the steps to start your own bokashi system.
It tells you everything you need to know about bokashi including why I choose to think of it as a method of food waste recycling that’s distinct from composting.
How does the Bokashi Composting Method Work?
Bokashi was developed in the early 1980s by Dr. Teuro Higa, a professor at the University of Ryukyus, Okinawa in Japan.
It’s an anaerobic (no oxygen) process that relies on fermenting or pickling food waste by typically adding a specially formulated bokashi bran, wheat bran, coconut husk or rice that contains special microbes to create a special anaerobic environment.
No matter the bran or rice medium, it has to be inoculated with microbes that thrive in anaerobic conditions to be effective for bokashi.
Typically, there are three types of bacteria that can be used for this composting process: yeast, purple non-sulfur bacteria, or the bacteria that produce lactic acid.
You can make bokashi bran yourself or you can buy bran that’s ready to use.
If you choose to buy inoculated bran, I like Bokashi Brothers because it’s well-priced, contains both wheat bran and rice, and the inoculant is from a diverse and well-established “mother culture” of microbes.
If you choose to prepare your own bran, it’s a straightforward process but the finished product won’t be ready for about 4-5 weeks. It’s well worth the wait if you have the time and the patience!
Bokashi Composting Method in 6 Steps
Bokashi is technically (and most effectively) a 2-part process that begins indoors and ends outside in your garden or traditional compost pile/bin.
Part 1: Indoor fermentation/Pickling
Step 1. Get a bokashi bucket
Unlike traditional composting, bokashi has mandatory tools. If you’re handy with a drill, you can make a bokashi bucket. You’ll need 2 5-gallon buckets with lids from Lowes or Home Depot.
If you’re not, there are commercial options. I like the SCD Probiotics Indoor Composter because it’s straightforward and not fancy. You can buy a 5-gallon SCD bucket for under $50 (plus they kick in a bag of bran).
The difference between a traditional indoor kitchen compost bin and a bokashi bucket is the spigot at the bottom (or the 20-30 drilled holes throughout if you’re making your bucket) to extract bokashi tea.
Step 2. Add your food waste and your bran
One of the best things about the bokashi composting method is that all food is equal…including meat and dairy. So add it all!
At the end of every day, mix your kitchen waste with some bran (a few tablespoons) and press it into the bucket. Add another layer of bran on top.
To accelerate and optimize the process, it’s recommended that you chop up big pieces of food into smaller pieces. Bones and other hard objects will take more time to ferment if left uncut.
Step 3. Cover your layers inside the bucket with either plastic wrap or a plate/lid.
Remember that bokashi is an anaerobic process so you want to severely limit the amount of air that comes into contact with your food scraps and bran layers.
To do this, you need to push down your food scraps/bran layer with a plate or lid every single time that you add material. You’re pushing air out and creating an environment that is essentially vacuum packed.
Your plate/lid should be very close to the same diameter as your bucket so that it’s a reasonably snug fit around the sides.
TIP: Use a lid with a handle on top (from a pot/pan) so that you don’t have to pry up the sides of a plate every time. You can also use a layer of plastic wrap to create the seal, but ya know, plastic…
Step 4. Seal the bucket closed
Step 5. Extract the bokashi tea
The entire process of fermenting/pickling a filled bucket of food scraps can take 10 days if you’re getting rid of soft and small pieces of waste. Depending on the nature of the waste, it can take up to 2 or 3 weeks (compared to 6-12 months to compost).
But the liquid (technically leachate because it’s the leaked byproduct of waste) that accumulates in the bucket during that period is both critical to the pickling process and a nutritious “tea” that you can use immediately.
Every two days, push down on the interior plate/lid/plastic to push the liquid to the bottom so you can extract it from the spigot.
The two best ways to use bokashi tea:
- Pour the tea (as is) down your sinks and toilets for better drainage.
- Dilute it to a ratio of 100:1 (water:tea) and water your plants. Just be sure that you really dilute it or else the liquid’s extreme acidity will kill your plants.
TIP: Use the liquid immediately as the valuable nutrients and trace minerals will start to break down quickly and then you’re just left with gross water.
Step 6. Repeat steps 2-5 until bucket is full
Keep adding food scraps and bran, and extracting tea until your bucket is completely full.
Let your bucket sit undisturbed so that the friendly microbes inside can do their thing for 10 days to 3 weeks.
TIP: Don’t be alarmed when your finished fermented bokashi doesn’t look like finished traditional compost. The final bokashi product will look almost identical to the original food waste. Remember that you’re pickling (preserving) waste – the bokashi method doesn’t decompose it.
Part 2: bury/use finished bokashi outside
There are two places that you can bury your finished fermented waste.
- Garden – in 2-4 weeks, the material will work gangbusters for your veggies and plants. But before then, it’s highly acidic so be sure that you don’t bury it where it could have direct contact with plant roots.
Ideally, you’d use bokashi as part of your regeneration process in a fallow bed. Dig a hole that is about 20 to 25 cm deep and add your bokashi. Mix with some soil and cover with the remaining soil.
- Traditional compost pile – it will work like a turbo accelerant because the matter that goes into the Bokashi would otherwise take months to fully decompose.
You can also feed bokashi to worms BUT you must introduce this new food to them very gradually so that they don’t die from the extreme change in PH levels.
Start with a tablespoon of bokashi in the corner of your vermicompost bin. Continue to gradually introduce more bokashi into their environment over the next 4-6 weeks.
What are the Differences Between the Bokashi Composting Method and Traditional Composting?
Bokashi and composting occur in 2 different environments and rely on different types of organisms. While some people think of Bokashi as a different method of composting, it’s actually a different method of getting rid of waste. Bokashi is a method of fermentation or a preservation (pickling) process. Here are some of the key differences between Bokashi and composting.
- Composting is a process where microbes are allowed to break down organic matter into smaller molecules in aerobic (with air) conditions. In Bokashi, anaerobic (without air) conditions are necessary for the bacteria to work.
- In Bokashi, there is no nitrogen loss, which is what happens in composting. This is because the activity of microbes is high in composting, compared to Bokashi.
- The microbes in compost use the energy in waste and convert it into carbon dioxide and water vapor, both escaping into the air as gases. During Bokashi fermentation, there is very little carbon dioxide produced.
- During composting, the organic matter produces heat energy which is usually lost although it’s quite beneficial to the plants. This energy is preserved in Bokashi and can be used to stimulate plant growth.
- In some cases, people use cold composting to minimize energy loss. However, cold composting doesn’t kill pathogens. In Bokashi, pathogens can’t survive in highly acidic anaerobic conditions.
- To start composting, you don’t need to add the microbes as they’re found everywhere. This is not the case with Bokashi as you have to add the microbes to get the process started.
- When the process is over, the waste left from composting is made up of large rather stable organic molecules with all the mineral nutrients preserved. The final product might take up to 5 years to be fully decomposed. In Bokashi, the end result is usually unchanged as the sugars have changed to acids, retaining all the nutrients along with the gases.
- For gardeners, Bokashi has more of the original nitrogen but compost contains more nutrients that have already started decomposition.
- Bokashi is a potent way of getting rid of kitchen waste but doesn’t work as well with garden waste.
What Are the Benefits of Bokashi?
Some people think that Bokashi is not an ultimate solution as it might seem even more complicated than regular composting. However, it’s actually more flexible and quite simple to master. Here are a few benefits of Bokashi.
Easy to Learn
Bokashi is done in small batches so you can monitor how the process goes. If, for example, you didn’t drain the liquid and your process was ruined, you can easily get rid of the batch, scrub the bucket, and start again.
Composting, on the other hand, is typically done on a larger scale. There are several variables that might affect the end product. These include pests, temperature, humidity, and the nature of the materials used in composting.
Once you have filled your Bokashi bucket, there is little to do except to drain the liquid. Things are different when you’re dealing with compost as you have to aerate/turn the pile to help the microbes get more oxygen so they can help break up the waste, continuously add material in the proper brown to green ratio, add water as needed, and then transport finished compost to the rest of your garden.
For composting to succeed, you have to find the right balance between brown and green materials to reach the adequate carbon to nitrogen ratio. This is not the case when you’re opting for Bokashi as anything can go in the bucket.
In composting, carbon-rich (aka “brown”) materials include straw, stems and twigs from the garden, sawdust, corn stalks, fruit waste, leaves, newspaper, and cardboard that should be free of dyes. Nitrogen-rich (aka “green”) materials include algae, alfalfa, hay, clover, grass clippings, coffee grounds, vegetable scraps, kitchen food waste, and manures.
Some items should be avoided in composting: meats, bones, oil and grease, pet waste, colored paper, onions, garlic, and citrus peels.
In Bokashi, however, it doesn’t matter whether you use raw or cooked food. Even bones, meat and dairy are great for the preserving process! This means that ALL of your kitchen waste will be recycled back into the soil to enrich your garden.
Bokashi can be done on any scale. You can do it on a countertop or in a special spot next to your garage. It all depends on the amount of waste you have and the setup you have chosen.
Most beginners prefer to work on a small scale until they master the process. Once you’ve done it successfully, you’ll probably be doing several buckets at a time or even opting for a bigger container.
While keeping an eye on your waste, you’ll get a clear idea of what you’re actually eating and what you’re throwing away. Bokashi will show you how much food you’re consuming and will also help you keep track of the food types that you consume the most.
If you aspire to a truly zero waste lifestyle (in the kitchen at least), bokashi should appeal to you.
How to Know that Something is Wrong?
Bokashi is easy but requires monitoring. You’ll know when your bokashi has gone wrong if it starts to smell very bad.
Successful working bokashi will smell sour but not foul…like you’re pickling food. If your nose starts to suspect something unsavory, you can attempt to remedy by increasing the amount of bran that you mix in, and layer on, food scraps. If this doesn’t fix the problem, discard the whole batch and start again.
Tips for Using a Bokashi Composting System
While Bokashi is typically easy to learn and master, there are a few tips that can make your job easier.
- It’s better to add too much bokashi bran than too little. This will promote and accelerate the fermentation process.
- Always chop bigger pieces of waste to facilitate the process.
- Avoid adding liquids and water. If possible drain all the waste before adding it into the bucket.
- Add fresh waste. Avoid adding rotten or moldy waste.
TIP: Food with white and green mold is fine. Food with black mold is not!
- Don’t add plastic or paper waste into the bucket.
- Keep the bucket in the shade.
- Wash the bucket after emptying it.
Should You Use the Bokashi Composting Method?
Bokashi as a method of food recycling is optimal if:
- You have far more food waste than garden waste
- You’re looking for an apartment composting alternative
- You don’t have space for an outdoor compost pile/bin
- You’re more likely to stick with a food recycling system that works in weeks as opposed to months
- You’re looking for the best way to recycle meat and/or dairy
- You like the idea of bokashi as a valuable supplement for an active vermicompost system
Although the bokashi method of composting does not break down organic waste like traditional composting, it is an excellent way to recycle food waste fast.
As long as you maintain your bokashi bucket, it’s an especially effective way to nourish your garden in a small space.