01. Getting carbon out of the air and into the soil

The most common question — ever — is What is bokashi? So let’s start with this.

Bokashi is a new way of using kitchen food waste to make soil. Great soil. Healthy, living soil that’s full of microbes and nutrients.

It’s the fastest way of making soil that I know about it.

And even though I’ve been doing traditional composting for years before starting with bokashi, the results are far better. Plus, it’s a lot easier once you figure out how to do it.

So: faster, better, easier.
But there’s one more thing that’s more important than all this.

It’s about carbon gases. Greenhouse gases. The carbon-based stuff in the atmosphere we really can’t afford to have more of.

Traditional composting creates a lot of greenhouse gases. Bokashi doesn’t. So if we look at the really big picture, this is important.

A traditional compost works with decomposition. If you put a lot of organic material in a pile if will rot, decompose, and eventually become soil. So far so good.

But the problem is that this takes time, and a lot of the original nutrients and energy are lost in the process. And some 50 per cent of the carbon in the pile leaks out as carbon gases, methane and carbon dioxide. They make their way into the atmosphere and as a result add to the problem rather than to the solution. Meanwhile, the rest of the carbon in the pile becomes soil organic carbon, the good side of the equation, the thing we are really in need of.

But the pity is that half of the ”goodness” of the pile is lost for no reason.

When we would really need all of it in the soil and none of it in the air.

While it may not matter that you or your neighbour add a few extra kilos of methane to the atmosphere, it does matter if you look at organic waste and composting from a global perspective.

We really cannot afford to be losing so much good ”soil” energy for no reason.

And we absolutely cannot afford to be producing such staggering amounts of greenhouse gases as a result of poor management of organic waste.

So, even from this perspective, bokashi is the answer.

Faster, better, easier, yes. But also a very smart way of using unwanted organic material to create valuable soil carbon instead of very invaluable greenhouse gases.

Bokashi is a process

As I said earlier, bokashi is a new way of making great soil from organic waste. Apart from all the environmental benefits, it’s quick and easy and universal: works pretty much anywhere.

Bokashi is a process. A three-step process that’s very simple and that you can do in any kitchen, small or big, in any country and under any living conditions.

It’s based on fermentation.

Which in turn, is based on microbiology: a whole bunch of so-called beneficial microbes do what they do best and restructure the components of organic material into other components. Then, in turn, they work with soil microbes to transform the new components into soil. Living, active soil, the best there is.

The first two steps of the three step process take place in the kitchen. The third takes place in the soil.

It works like this:

Step one: You need a bokashi bucket (more later) and some proper bokashi bran (more later on that too). And food waste: whatever you have going in the kitchen basically. It will all work.

The easiest method is to collect up the day’s food scraps in a container on the kitchen bench and add them once a day or so to the bokashi bucket. Sprinkle a tablespoon or two of bokashi bran into the bucket before you start then the same again after every liter or so of food waste.

It’s worth chopping up the food scraps a little as it will help the microbes get a grip and do their work. If you have big quantities of any one thing, try to alternate it with some other kind of scraps.

It really doesn’t matter how little or how much food waste you generate each day, a typical volume is around one liter and that means you’ll fill your bucket in 10 days or so. But every household is, of course, different. If you need to go away for a few days, it doesn’t matter. Just carry on when you come home again.

Keep filling the bucket till it’s full. Press down the contents as you fill the bucket, but not so hard that it prevents moisture from finding it’s way down to the tap, if you have one.

That’s it for step one!

Next up: Filling your bokashi bucket – important things to keep in mind

What is bokashi?

Bokashi is a great way of making rich, living soil out of everyday food waste. There are other types of bokashi used in other applications auch as agriculture, it’s a broad concept. But it always involves EM microbes, fermentation and organic material.

Our focus here on this blog is on food and organic waste from households, restaurants and markets.

When this type of organic material is layered with EM bokashi bran in an airtight bucket or barrel it ferments in a couple of weeks. There are no issues with smell or hygiene and you can do this indoors if you wish.

The fermented material is then dug down straight into the ground or a planting container where it is rapidly transformed into soil.

Ideal for planting, or for later use as a humus-rich organic fertiliser.

The truly valuable thing is that every bucket of bokashi you dig down helps to build carbon in the soil, and make it far more alive and productive. All good things for your garden here and now, and for the future of the planet.

Biochar and bokashi = great combo

Anyone here know about biochar? I’m in Myanmar and they’re using a lot of biochar made from rice husks as a potting mix base. I’m not sure how they’re making it; if its real pyrolysis (sort of burning it without oxygen). How can you tell, do you know?

Time to stop using peat!

From a broader perspective, it would be great to stop using all this peat moss in potting mixes, as we’re doing in other parts of the world. Crazy.

You can obviously make biochar with a lot of different materials but what is often not talked about is that you have to charge charcoal or whatever with nitrogen before you dig it down in the ground. Otherwise it will take the nitrogen it needs from the soil and your plants will suffer.

Good quality charcoal is great in combination with bokashi. Used in a bokashi bucket it will absorb a lot of excess liquid, which will also load it with nitrogen. This means you can use a bucket without a tap if you want (cheaper, easier). Microbes love hanging out in charcoal and I’m assuming the same holds for other forms of biochar.

And biochar is a great soil additive, balances moisture and nutrients in the soil and works really long term.

If you’re going to use it in a bucket, crush it a bit first (charcoal is often made for cooking purposes and is in big chunks). That way the microbes can get it easier and there will be fewer air pockets.

Check your source!

Oh, and another thing. Check that the source of your biochar is ok, especially in the case of wood-based biochar. Ethical forest and all that. Makes no difference to the microbes but all the more to the planet.

Any thoughts on this? Have you used biochar in your soil?

Footnote: we had an interesting discussion on our facebook page Bokashiworld this week, a lot of good input from Walid Gabr who has done a lot to spread the bokashi message in Egypt and the Middle East. Here’s a link to the discussion.

These were a couple of biochar videos he recommended, they’re good!

Nature farming and EM workshop

The last days I’ve been at a Nature Farming workshop at the EM center in Saraburi, just outside Bangkok. Interesting and very inspiring.
Have a ton of pictures to share so I’ll post them in small batches.
Nature Farming and EM is an integrated thing, but the nature farming movement has Japanese roots going back a hundred years. It’s ALL about taking care of soil in a natural and smart way, working and living in harmony with the animals and plants around us, and also with ourselves.
The farm at Kyusei has been running for nearly 30 years from memory, totally organic, and here they’ve been systematically been using EM since the early days. It’s 170 hectares, big!!, and includes a number of demo farms (S, M, L) where many Thai farmers have and are being trained.
This workshop is run twice a year, so it was a privilege to be there. We were a small group of 20 or so from all over Asia and me from Europe: soil scientists, biologists, forward thinking organic farmers wanting to bring about agricultural change in their home countries, and a number of very skilled technical guys from Japan. I was representing bokashi in Sweden.
So extremely interesting!
And the food was amazing.


Toru Koshoji, head of EMRO Asia. Kyusei Nature Farming Center.


The chooks are so healthy! They get EM in their feed and in their drinking water, the green snacks come from the green manure and crops in the crop rows. Kyusei Nature Farming Center.


With Kentaro Sakibara, course leader and technical guru from INFRC, the International Nature Farming Research Council, and Anisa, from Malaysia. She’s a professor of soil science and one cool woman. Like the hats? Kyusei Nature Farming Center.


EM Thai style. The production facility is nearby. Kyusei Nature Farming Center.


It’s so big we got to ride around on a tourist train. Just as well, it was pretty hot. Like the hats? Kyusei Nature Farming Center.


Obligatory group shot😉 Kyusei Nature Farming Center.


Starting up with bokashi

Bokashi is actually really easy.

But the first bucket or two you do often feels quite strange. It’s not natural for us to squirrel away food waste in a bucket in the kitchen, and we’re trained to think bacteria is risky and any rubbish in the kitchen should be removed immediately, before it starts to stink.

Then after a couple of buckets, your whole world changes. Food waste is not “rubbish” any more, it’s the best resource you have in the kitchen.

And microorganisms become your new best friends. In the kitchen, and out in the garden. Woohoo!

So, what should you expect when you start with bokashi?

Give it time. Maybe the first bucket or two aren’t perfect, maybe you don’t quite get it right. But after a couple of buckets you’re an expert and will get it right every time. Don’t overthink it, this is just food waste, right? It will ALWAYS be good soil in the end, even if you mismanage a bucket or two and they smell more than they should. No big deal.

Don’t expect that you’ll get soil in the bucket! We’ve all thought that at some stage, but this is not how bokashi works. Fermentation is a kind of conserving process (think sauerkraut or any other kind of fermented veggies). Your food waste will be preserved in its bucket, and even after a few weeks it will still look pretty much the same. I admit, it is a bit weird that you can recognize the leftovers of that lunch you had when the family was over, or that time you made juice and the bucket filled up with orange peel. But that’s just the way it is.

Bokashi is a two-step process. The first step takes place in the bucket: it’s a fermentation process, needs to be airtight, and there won’t be much to see (the changes are all happening at protein level.) The second step takes place when you dig the bokashi down into the soil. Then the soil microbes meet the fermentation microbes and a transformation process begins. The bokashi is essentially absorbed into the soil. It happens quickly and easily because of all the (invisible to us) pre-work that’s been done in the bucket. A few weeks usually, depending on your soil temperature.

I’ve written a lot elsewhere about WHY we do bokashi, about the importance of getting carbon into the soil and creating great soil for growing plants in. But the joy of seeing this happening is really something. So, just hop in and do it!


Right. So you’ve filled your bokashi bucket in the kitchen. There are many types of buckets, each country has a different style. In Europe, we typically have 16 liter buckets with a tap, in New Zealand it’s more common with a double bucket with drainage holes in the internal bucket. Either way the concept is the same.

You can also use “normal” buckets without drainage, these work just as well and you can usually get them free. But it’s essential to take up the moisture, some form of charcoal (chemical-free) is the best, newspaper or wood pellets also work well.

So, with bokashi there’s only two real rules, and if something is going to go wrong it will generally be one of these two:

  1. An airtight bucket is really important. Bokashi fermentation is an anaerobic process so you need a good lid.  If you don’t the food waste will probably start to rot.
  2. Too much humidity in the bucket will make it smell. No worries really, as your bokashi will still make great soil. But a bit unpleasant. Make sure you drain the bin of liquid regularly. And if there’s a lot of condensation, lay a newspaper or egg carton on top to absorb it.

You’re going to need two buckets so you can rotate them. After each bucket is filled (typically takes a week or ten days for a small family, but can be anything up to a couple of months) it needs to be put aside for a couple of weeks while you fill the other. This allows the microbes to continue doing their fermentation work. After that, the bucket is “stable”, you can dig it down, make a soil factory, store it as it is for a few months. Whatever works best for you. Bigger families often need three or four buckets to cope with their bigger volumes.

Sometimes you’ll get a white fluffy mould in your bucket. That’s fine. Usually just means your bucket has been standing for a while. Or that it’s not super airtight (but tight enough to do the job). It’s just living microorganisms doing their thing, and nothing to worry about. If you get a batch of green, black or blue mould however, that’s another story. Scrape it away and get rid of it; if it’s gone through the whole bucket, sorry, but you’ll have to ditch that batch. Usually it’s caused by too much moisture in the bucket.


While you’re filling your bucket and while it’s “on hold”, it will produce plenty of bokashi liquid. How much depends obviously on what you have in your bucket. But it’s great stuff, the garden loves it as it’s a real nutrient boost. Drain it off regularly, preferably into a plastic bottle with lid (the less air the better), and use fairly quickly in the garden. Dilute 1:100. That’s 1 deciliter in a 10 liter watering can.

If you’re not going to use it immediately, put the bottle in the fridge. And if it’s going to really be a while you can freeze the liquid. Ice-cube bags aren’t so silly — as long as you label them!

Photo: Jenny Harlen

Then it’s time to dig it down. Honestly, this couldn’t be easier. Just dig a bit of a hole, ditch or whatever. Empty your bucket. Spread it out reasonably evenly and cover with soil.

It’s often a good idea to throw something heavy over the top for a couple of weeks, a metal grid, thick sheet of plastic, a couple of planks you have handy. Just in case the family dog gets curious or, if you live in wilder parts of the country, you have inquisitive foxes or badgers that like to have a poke around. Rats and mice are not generally attracted to bokashi due to the low pH, but if they are hungry enough they’ll find it, so just feel your way forward a bit on this one.

Photo: Jenny Harlen

If you like, you can top up with a sack of garden center soil or soil from another part of the garden, whatever works best for you.

Then it’s time to plant! Just one rule here to observe, and that’s that plants shouldn’t come into direct contact with bokashi the first couple of weeks. It’s to do with the pH. Fresh bokashi is on the acidic side, too tough for most plant roots. After a couple of weeks the pH has neutralized (it will be the same as the rest of your soil, so you won’t end up with acidic soil) and the plants will be happy to be there. So wait a couple of weeks before planting. Alternatively, dig the bokashi down a bit deeper so that newly planted plants (or newly sown seeds) will take a couple of weeks to reach it.

Depth? Decide the depth you dig down your bokashi based on the needs of your plants. You want their roots to strive a bit for the nutrition, so lower rather than higher in the soil. Another reason for digging deeper, say 30-40 cm, is to make it less interesting for the dog, etc. But that can just as easily be prevented by laying something over the soil.

How long will it take for the bokashi to become soil? Four weeks is often a good guideline in a warmish climate. More like six to eight weeks in a Scandinavian spring or autumn, possibly as fast as two or three in a hot climate. The more you mix the bokashi with the soil when you dig it down, the faster it will go. And the smaller pieces you have in your bucket, the faster. But, really, it’s not a big deal. It will all be soil eventually. And even if you still have bits of food down there in the soil, your plants won’t mind. They can access the nutrients anyway.

SO. This is the basics. After you’ve done a bucket or two, you’ll get this. Then you can start finding a flow that suits you. The most important thing is to make it easy. Bokashi is something that should fit easily into everyday life, not make an already busy life even more stressful. Try a few different concepts for digging down your bokashi, have a go at a soil factory (it’s fun!) and see what works best for you at different times of year.

Bokashi is a really forgiving process. It’s pretty hard for it to go really wrong. And even if it does go a bit wrong, learn from your mistake, dig it into your garden anyhow and it will be soil in due course.

You’ll know it’s working because your plants will tell you. The difference in how they grow in really good soil, compared to how they grow in poor, lifeless soil, is really quite extreme. Most likely, you’ll just wonder why you didn’t start earlier!

READ MORE: Drain your scraps before they land in the bokashi bin!

READ MORE: Quick and easy soil factory

Organic recycling in Europe

I was out wandering in Bolzano, Italy the other day and saw this great example of organic waste collection. Very simple, it was just a brown bin outside the door of an apartment building in the old town.

It just made me happy to see it, that’s all. So many cities say it can’t be done, it’s all too hard, and the councillors just look the other way as truckloads of organic waste just end up in the normal bin. I’m not sure what the collection arrangements are for this, but I assume a truck comes round fairly regularly and collects it. After all this is Italy, even if Bolzano is up in the Alps (and a lovely city at that!), it’s been a hot summer, and food waste starts stinking pretty soon if you don’t do something.

Photo: Jenny Harlen

A few days later I’m in Ljubljana, capital of Slovenia (actually the smallest capital in Europe, and definitely one of the cuter), and see this. Organic waste collection built into the streetscape. Very cool!

I’m not sure what the collection arrangements are here either, but I’m assuming the metal plates lift up somehow and the container or whatever can be emptied into a truck.

This is not a bokashi-based system, but I do know that in a town in Croatia, just down the road, the local council is experimenting with bokashi in combination with this sort of urban organic waste collection. Householders all get a free bokashi bin (a nice one with taps and all) and can either use the fermented bokashi in their own garden or allotment or can empty it into the council collection system (brown bins in their case).

The upside for the council is that they don’t have to collect the organic waste so often because it is more compact and doesn’t smell. The upside for the householders (those not using the bokashi in their own gardens) is that they don’t have to go out with their organic waste every day. They can just quietly fill the bin and empty it when it suits.

Also very cool!


These collection stations have solar cells and some kind of card reader on the side. I’m guessing that local residents all have the right kind of card and that stops the bins being used by non-residents. IMG_5153

This, by way of context, is Ljubljana on a sunny day in September. Damn fine city, great beer, worth a stop if you ever get the chance!IMG_5154

What’s bokashi all about?

The other day, I received a question from a student writing an essay about bokashi. What’s it about, basically?

So very cool that this is happening! That students are writing essays and dealing with these all important issues of soil, food waste, sustainability, in a hands on, practical manner.

Anyhow, just to get the conversation started, this is what I replied. There will probably be more, as we all know here once you start getting curious about bokashi it’s hard to stop.

But in case there’s any more students out there looking into bokashi for the first time, here’s a few words to get you started on your journey. You’re more than welcome to come back with more questions, either here or in the Facebook group “bokashiworld”.

The big deal with bokashi is that, globally, it’s a really good way to get carbon back into the soil. Food waste is a really big problem, everywhere, and so is the declining level of soil quality (and volume). So with bokashi you can solve two problems in one by using the food waste to improve the soil.

Of course, various forms of composting have always existed. They’re fine, up to a point, I mean at least it’s good that people are doing something with their garden and food waste. But the problem with traditional composting (where you put everything in a pile and it rots and turns into soil) is that a lot of nutrients are lost in the process. And a LOT of the carbon in the organic material is transformed into carbon dioxide and methane and released into the atmosphere. Bad!

With bokashi, there are two big differences. First, the fermentation process actually improves the nutrient value of the food waste, makes it a better resource for the soil. Second, because it is first in a bucket and then dug down into the soil, none of the bokashi is converted into atmospheric carbon, it all becomes soil carbon. Which is really, really good.

The other thing is that for most people, especially those living in an urban environment, bokashi is much easier and more convenient to do than traditional composting. In urban centers there is more or less no good soil or organic fertilizer available, and so to use food waste to create soil is just genius.

Just some startup ideas, hope it helps you! What country are you in? What are you studying?

Good luck! /Jenny

READ MORE: Starting up with bokashi

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