Do you have any other Earth Bokashi or composting questions?
“Bokashi” means “fermented organic matter” in Japanese. Developed in the 1980s, bokashi composting is a fermentation method. Food waste is added to air tight bins, layered with “Earth Bokashi” and the bin closed. Beneficial microbes in the Earth Bokashi mix then activate and start a fermentation process. These microbes stop the food waste from rotting and smelling.
After fermentation, contents can be composted with garden waste, dug directly into your soil, or fed to composting worms.
Please note that bin contents are essentially preserved and will only break down once the contents have been processed outside of the bin.
You can listen and learn more about bokashi by listening to our podcast.
Because contents are fermented they do not turn into compost in your bin. Only when contents are added to your compost heap, dug into soil, or fed to composting worms will the contents turn into compost.
Fermentation is an ancient food preservation technique – think sauerkraut or kimchi – as is the bokashi composting method.
Fermented contents of the bin are populated by beneficial microbes and will add valuable life to your soil and also, because fermentation is essentially a pre-digestion method, turn back to soil very quickly (just as our bodies process fermented food much more easily than other cooked or raw food.
Nothing could be easier. Just follow three very basic rules:
Remember that all food waste can be added to the bin. So you don’t have to worry about what you can or can’t put into the bin. Everything goes!
Just follow the instructions and you’ll be fine. The instructions, above, are also printed on Earth Probiotic’s bin for easy reference.
The fermentation process generates a leachate. The strainer in the bin separates the leachate from the food waste. The tap allows you to drain off this leachate.
The leachate, or “bokashi juice”, is a wonderful and powerful product. You can use it as a liquid fertiliser or as a drain cleaner.
This is a simple and easy process and requires no glue or sealant.
Simply push the tap into the hole on the bucket. When you hear a “click” it’s inserted properly and will be leak proof.
If you’re struggling to insert the tap simply leave the bucket in the sun for 10-15 minutes to soften the grommet. you can also use a hair dryer for this purpose. The tap can then be pushed in with ease.
Bokashi composting is a two step process. Once the food waste is fermented you can do the following:
While you’re filling the bin keep it in your kitchen. It doesn’t smell and this is a convenient place to keep it while you’re busy cooking and cleaning up.
Once the bin full store it in your garage or a store room for two weeks (this is necessary to complete the process and ensure that the last layer of food waste is properly fermented before it is composted).
Do not store in direct sunlight. It will get too hot and kill the microbes. These need to be kept alive to keep the process going and keep the bad bacteria from growing in the bin.
You need a minimum of two bins. Why? Once the first bin is full it needs to stand for two weeks to finish fermentation. During this time you can then start filling your second bin.
Each bin will hold around 18kg of food waste. If you generate more than this you can always purchase an additional bin.
Or if, like us, you don’t run your composting activity like clock work, then you might need a couple of extra bins.
Your nose is the best indicator to check all is well in your bucket. If it smells rancid then add two handfuls of Bokashi to try and reverse the process.
If the bucket continues to smell bad then you will have to get rid of it by digging a hole and adding the bucket contents to it. Mix with soil, add another handful of Bokashi bran and cover with the rest of soil. If you have nowhere to ‘bury’ it then you have to dispose of it in your weekly refuse bin.
Yes, the bokashi bran is rich in beneficial microbes which have grown on and in your food waste.
When you add the contents to your compost heap you are adding millions of beneficial microbes into your compost heap (as well as micronutrients and organic matter from your kitchen). The microbes in the bokashi food waste will work with other naturally occurring bacteria and fungi and to accelerate your composting activity.
There are a number of large and small devices which promise to turn food waste into compost in 24 hours.
This is not possible. The UK food waste company, Tidy Planet have an extensive FAQ that deals with this issue. As does America’s Green Mountain Technologies.
In the composting process, organic waste goes through natural—which has been perfected over millennia by nature—stages: mesophylic to thermophilic to mesophylic to mineralisation.
This natural process can take anything between 10-20 days even under controlled conditions.
“Composting” is defined in the Waste Management Licensing (Scotland) Regulations 2011 (WMLR), as–
“the autothermic [i.e. self-heating] and thermophilic [i.e. 40-80°C] biological decomposition and stabilisation of biodegradable waste under controlled aerobic conditions that result in a stable sanitised material that can be applied to land for the benefit of agriculture, horticulture or ecological improvement”.
(Source: Tidy Planet).
24-48 hour processes are essentially dehydration process and produce a dry powder which is not stable and does not benefit soil. This substance needs to go through a second treatment stage.
Green Mountain Technologies cite research conducted by Loyola Marymount University in the USA which concluded that:
“Ultimately, the study revealed that the unprocessed dehydrated food waste samples were not suitable as a soil amendment on LMU’s campus. Rehydration of DFW produced large quantities of fungus, an outcome not acceptable on LMU’s grounds. Although dehydrated, the material is not decomposed to a stable state. This is a key distinction. While dehydrating LMU’s preconsumer food waste is a good first step towards sustainability, further processing of this material is needed before it is suitable to be used as a soil amendment or for another purpose.”
Essentially then, “24 hour compost” is simply dehydrated organic (food) matter.
This is fine if you are looking to reduce volumes going to landfill. And are prepared to accept the significant amount of energy required to dehydrate large volumes of food waste fast. And also accept that this matrix needs secondary processing if it is going to be used as a soil amendment.
“24 hour compost” isn’t compost.
White mould is good. The white mould is a beneficial fungus which helps suppress pathogens. If you have white mould it shows that your fermentation is going well. When added to soil this beneficial fungus helps with water retention and helps bind soil together.
Black/blue/green mould is bad. It shows that the fermentation has not worked properly. This is a rare occurrence and is the result of the bin not being closed properly (not anaerobic), not enough bokashi has been used, and/or rotten food has been added to the bin.
The liquid removed is loaded with microbes and nutrients and makes an extremely effective natural fertiliser.
Bokashi juice is acidic and should be diluted as follows:
1:100 for lawns and veggies. 1:300 for gardens and pot plants. 1:1000 for any sensitive plants.
Use as a soil drench and not as a foliage spray.
DO NOT USE THE BOKASHI JUICE TO FERTILISE FYNBOS.
Use the juice within 24 hours as it contains living bacteria, after this period the Bokashi juice loses its effectiveness and will go off.
Use undiluted and pour down your drains. It will help keep the drains clean and odour free. It is very useful in preventing sludge from building up and blocking drains and is a good way to minimise problems in your septic system.
The amount of juice will depend on the moisture content of the food you add. For instance, high moisture fruit such as watermelon will produce more juice than old toast.
In winter your digester will produce less liquid than summer.
This is for two reasons: (a) winter food tends to be starchier and summer food contains more fruit, vegetables and salad which have higher moisture content, (b) the cold of winter makes the microbes less active than in the warmth of summer.
You can add all cooked and uncooked food to the bin. This includes meat, small bones, sea food, citrus, coffee grounds, yoghurt, ice cream, dairy, cheese rinds.
Basically anything that comes from an animal or a plant.
You can even add paper napkins as long as they have not been used to wipe up chemicals.
You should not add the following:
Lucky you! We’re envious!
There’s no need to worry. Just add a layer of Earth Bokashi to the top layer and close the bin. That’s it.
The contents will continue fermenting, won’t rot or go off.
When you’re back from holiday just continue as before.
Why not take your bin with you? We do this when we go camping or stay in self-catering cottages. Then we bring it back home with us. We just can’t throw the stuff away. And why waste those wonderful nutrients?
The microbes within the bokashi bran suppress putrefaction, pathogenic and methane-producing microbes, dramatically reducing the green- house gasses that are produced.
When you compost with bokashi, you are fermenting organic waste anaerobically at a low pH so greenhouse gas production is drastically reduced. Methane-producing microbes can’t survive at a low pH, so no methane gas is produced.
As a general rule, any fermentation process will produce carbon dioxide — CO2. This is as true for fermenting cabbage to make sauerkraut as it is for using bokashi to ferment food waste.
We have found that this occurs more often during the final two week fermentation period (when the bin sits). During this period the lid is not opened and thus a build up of CO2 can occur.
You will find that your lid will swell (or pop-off) under the following conditions:
A swollen lid just need to be lightly ‘burped’ (gently unsealed or the tap slightly opened) to release excess CO2. It is no reason for concern.
While CO2 is a greenhouse gas it is much less impactful on the environment than methane (CH4). While both are anaerobic processes, methane is produced by rotting waste vs. fermentation.
Check out our outlet list here.
Yuppie Chef, Takealot and Faithful to Nature also stock our Earth Bokashi kits. You can also purchase from shop if you are not near a convenient retailer.
“Bokashi” can be made from many different carriers. All that is needed is a mix of beneficial micro-organisms and a carrier. A quick search on Youtube will show that bokashi can be made from newspaper scraps, wheat bran (the convention in South Africa), rice husks (common in South East Asia), saw dust/shavings, brewing malt, etc.
Our philosophy is that we need to source as much of our ingredient mix locally. This not only reduces our carbon footprint but also reduces waste. It also gives us control over what is going into our mix – we have direct knowledge and familiarity with everyone in our supply chain.
| Earth Bokashi | Other bokashi |
|---|---|
| Indigenous microbes | Imported microbes |
| <10% wheat bran | 100% wheat bran |
| C:N balanced composting mix | Not part of formula |
| Little to no fermentation odour | Mild to strong fermentation odour |
| Categorised microbes | Uncategorised microbes |
In theory yes. But we don’t.
1. You shouldn’t use compost that contains dog-poo into a food garden (risk of parasites).
2. It’s really smelly and we don’t want to be in such close proximity (although we love our Shetland Pony sized Giant Schnauzers).
We dig a hole then add the poo, sprinkle with a handful of bokashi and then cover with a layer of the excavated soil.
If you are interested, here’s a video on how to build a dog poo composter in your garden.
Do you have any other Earth Bokashi or composting questions?
The Earth Cycler is a flow-through continuous composting in-vessel (IVC) composting machine. The Earth Cycler has been designed specifically to allow for the on-site composting of food waste. Key features of the Earth Cycler are:
No. The Earth Cycler works automatically and operates on a timed repeating cycle which should not be interrupted.
The composting cycle includes a ‘resting’ period of 180 minutes (3 hours). This is necessary to establish a healthy microbe population in the the matrix. It the matrix sits for longer than this period there is no need to worry. However, if power to the machine is interrupted for longer than six hours:-
The Earth Cycler is designed to manage food waste. However, it can also process shredded garden waste up to the daily maximum load limit of 130kg (+ carbon). If you are going to add garden waste to the Earth Cycler follow these guidelines:-
You should only add organic/food waste and NO glass, plastic or metals.
You also should not add:-
The Earth Cycler does not rely on “forced aeration” (blowers) or additional heating. Both of these require a lot of energy. Rather the Earth Cycler relies on natural bacteria to heat the matrix. For aeration, the Cycler uses small fans simply to ensure adequate airflow (and air replacement).
Generally the Earth Cycler will use less than 1kW per day energy.
The maturity of the compost discharged depends on a number of factors:-
As a general rule the compost coming out of the Earth Cycler will be hot (active) and will need to finish (mature) outside of the composting machine.
The longer the matrix stays in the machine the more mature it will be
The Earth Cycler (standard model) weighs the contents of the machine. When the contents reach 650kg a banner message will appear on the control screen telling the operator to discharge. For the base model, the operator will need to keep track of the weights added to the machine.
Only the back 1/3 of the mix should be discharged. Once the operator starts seeing that the output is fresh and not composted the discharge process should be stopped. And the last part of the discharge loaded back into the composter.
Yes! The output from the Earth Cycler will add key nutrients to your compost. And, because it is hot and packed with beneficial microorganisms, it will accelerate the composting processing time.
You will end up with better compost faster!
The CN ratio is the carbon:nitrogen ratio.
While in nature “compost happens”, if you are managing this process at your business or home, you need to balance these two elements. If you have too much nitrogen (N or green material) the process will be smelly, too hot and will lose nutrients. If you have too much carbon (C or brown material) the process will be very slow and a woody dry low nutrient compost will result.
The micro-organisms (bacteria and fungi) in your compost heap need carbon for energy, and nitrogen for cell growth and reproduction.
Having the right CN balance means that you will produce a non-smelly nutrient rich compost faster
No. The C in the CN ratio refers to carbon which can break down into soil. This carbon is accessible as a food source to microbes and fungi.
Charcoal doesn’t break down and can last for decades if not centuries in the soil.
When added to soil charcoal C is beneficial as it helps with water retention, holds nutrients, and provides an ideal home for the growth of beneficial micro-organisms.
