Troubleshooting: What to do if you bokashi bin goes bad

4-step Guide to Bokashi CompostingBy following our 4-step how-to guide included for free with our bokashi starter kits, most people will enjoy successful results every time with their bokashi composting.  But if problems arise, don’t despair!  This page will answer and address the most common problems that might occur.

Bokashi composting is all about creating an optimal environment for the healthy bokashi microbes to thrive, and in doing so to convert your food scraps into nutrient rich pre-compost.  Remember that every climate is different, and not everybody creates the same type of food scraps, so there are no hard and fast rules for any composting process.  But after a couple of tries, most people will easily find the rhythm that works best within their kitchen.

How do I know if my bokashi compost bin has failed?

If you open your bokashi compost bin and you smell a foul, putrid odor or you see lots of blue/green mold, then something has gone wrong. A successful bokashi bin will smell pickly and/or yeasty and may have white mold visible (no visible white mold does not mean that it has failed).

Most common reasons for bokashi compost bins to fail


Make sure you chop up your food scraps before putting them in the kitchen composter.  Large items will compost, but will take longer to ferment than smaller items.  2 inch pieces are acceptable, but 1/2 to 1 inch in pieces are even better.  Remember that as vegetable and fruit skins are a natural protector, they will limit the bokashi microbes from entering as well.  Items like lemons should be chopped into quarters before putting them in the kitchen composter.


Excess air is bad for the bokashi process.  The kitchen composter should be opened and closed as little as possible, and for as short a time as convenient, while you are loading it and until it is full.  Do not leave the lid open unnecessarily.  It’s best to collect your food scraps in a bin or bowl on your kitchen counter, and just once a day, or better yet every other day, load them all at once into the kitchen composter.  And try not to open the kitchen composter at all during its sealed two week fermentation time.


To keep excess air away from the food scraps within the kitchen composter, its ideal to place something to act as an air barrier on top of the food scraps.  Use a plastic bag (recommended), piece of cardboard, or even a kitchen plate placed on top of the food scraps, as you are working to fill the kitchen composter. And leave the item there once the bin is full during  its two week fermentation process.  Be sure to PRESS DOWN hard on the covering barrier as you add food layers, as this will help squeeze air out of the food scraps in the kitchen composter (the covering plate will also serve to keep your hands clean while doing this).


A pile of Bokashi Living's premium bokashi bran

You can never add too much bokashi bran to the kitchen composter.  In fact,  more is better, especially when dealing with food scraps that rot easily (like meat).  At a minimum, at least be sure that you have a dusting of bokashi bran mixed evenly throughout the food scraps that are in the bin.  As you add the food scraps, sprinkle the bokashi, and mix slightly to ensure even coverage.


The kitchen composter should be kept away from extreme temperatures.  Room temperature is ideal for the microbes to thrive.  Keep it inside during cold months, and out of direct sunlight in the warm months.  Colder temperatures will not stop the microbes entirely, but it will slow them down.


Inside the kitchen composter:  most food scraps should successfully complete the precompost process in two weeks.  But some might take longer, especially if they are not chopped well enough.  Try leaving the food scraps for an extra week in the kitchen composter.  Longer fermentation time in the kitchen composter is always beneficial.

In the ground:  Once your precompost has been transferred to your garden, two weeks is usually all it takes for the majority of the items to be assimilated into the soil web.  However, if the temperature is cooler, or the food scraps are not fully precomposted, it might need longer.  An extra week in the soil should finish it off.

Further help and troubleshooting

Rodents are finding my buried pre-compost!

Rodents are curious and hungry.  They will often dig around anything that looks or smells new in your garden.  Bokashi precompost is acidic, and should not taste good to them.  If rodents have dug up your first batch of precompost, even after following the steps above, very often they will realize their mistake and not return.  However, if they dig it up more often, then you can easily solve the problem by ensuring the following:

  • let the precompost ferment in the kitchen composter for an additional week before transplanting to the garden or compost heap.  This will ensure complete fermentation.
  • bury the precompost deeper.  At a minimum, for rodent protection the precompost should be buried 6 inches below the surface. At that depth, the smell should not be inviting to them.  Bury deeper if you have particularly aggressive rodents.
  • try placing a piece of netting on top of the soil where the precompost is buried.  You can secure the corners of the netting with stones.
  • and remember that once an animal realizes that bokashi precompost is not easily available to them as a food source, they will move on.

My precompost smells rotten, and there is blue/black or green mold in it:

This is a sure sign of a failed batch, and it should be discarded (note that white mold is good and is a sign of a successful batch and very healthy microbes).  Be sure to follow the steps above, and in particular see that your lid is tightly sealing itself, the kitchen composter is not cracked, and that the drain spigot is kept closed.  As well, it’s likely that not enough bokashi bran was added to the food scraps, or mixed evenly enough throughout the food scraps.

My drain spigot leaks:

The drain spigot works with simple rubber washers.  For closing:  A simple and light finger tighten is all that is needed to seal the bin.  Over tightening can cause the inside washer to ‘roll off’ the sealing thread.  By disassembling the spigot, you can fairly easily reposition the washer if it has rolled off.  For opening:  half a turn is all that is needed to open the drain spigot.  Over turning it can cause it to become unthreaded, and possibly remain in the ‘open’ position.  If your spigot is draining by itself, then this is likely the scenario.  Simply push in on the spigot handle while tightening, and the thread should re-engage itself properly.


Remember, the bokashi composting system relies on a natural, living process and sometimes problems occur for not particular reason. If your bin goes bad, don’t despair simply pencil it down to bad luck and try again.

Order now! Find all your bokashi composting supplies in our online shop.

28 thoughts on “Troubleshooting: What to do if you bokashi bin goes bad

  1. Thanks, this is a really helpful post. Over the winter, I was concerned that the bin wasn’t getting any mould, so I thought is wasn’t working and was thinking of stopping. Having read this I realise that it was working fine and I will carry on bokashiing. Its really a good way of getting rid of smelly food waste.

    1. Great to hear it! As long as there is no blue/green moldy or foul, putrid smell then you can be confident things are working well.

      1. So. What do you do, exactly, if it goes bad. I forgot to drain the leachate out of my home made bokahi system made from home Depot buckets for a couple days and the whole thing smelled putrid. No amount of washing seemed to fix the problem. Should I throw out what is in there? Or bury it? Any thoughts on cleaning the buckets?

        Thank you

        1. So you’ve drained the leachate and buried the pre-compost but the bin itself still smells? If so, have you tried leaving the open bin out in the direct sun; sunlight is amazing! Also, have you tried setting up your bokashi bucket again. The bokashi microbes and the anaerobic conditions will also help to kill the bacteria associated with rotting and the putrid smell.

          On another note, I’m surprised that leaving the leachate for a couple of days caused the whole bin to go bad. Was it starting to smell beforehand?

          1. Not that I noticed, but it’s possible. I think the scraps I put in there were too whole to get digested appropriately. Could that have been the problem?

  2. We recommend that you cut food waste into 1-2″ pieces. The larger the pieces the longer it takes to break down. If you are adding larger pieces then be more generous with the amount of bokashi bran that you add, and expect it to take a little bit longer to ferment and to break down after you bury it. And remember, skins and peels create natural protection for fruits and vegetables. Make sure to chop up any whole fruits/veggies before putting them in the bokashi bucket so that the microbes can get at the flesh inside.

  3. I don’t have a garden only my patio, would I be able to make compost just leaving it in the bin? If so how long roughly would that take?

    1. Hi Elizabeth,
      Thanks for the question. The food waste in the bin is fermented and you need to add it to garden soil for the final stage. However, this does not mean that you need a garden. Many people make a soil factory to finish off their fermented food waste. This (put simply) is a rubbermaid container in which you mix your soil and bokashi fermented food waste. Read more here

      Hope that helps 🙂

  4. Hello,

    We are trying to start a Bokashi composting system for our small guesthouse/B&B. We produce a lot of food waste/plate scrapings during breakfast service and need an efficient way of dealing with it – will it harm the process if the bin is left open during service (around 2 hours) as waste is added gradually, and contents then squashed, sprinkled and sealed at the end of each morning? It will take approximately 2-3 days to fill each bin, so we are thinking that the contents will not have time to putrefying in that time, even though bins will obvs be exposed to oxygen? Keeping a separate bin that needs decanting into the Bokashi every day will simply not be practical. Many thanks in advance for your advice.

    1. Hi Jennie,

      Thanks for your question. I responded to your FAQ here.

      Please let me know if you have any follow up questions. We would love to hear how you get on 🙂

      Nicki and the Bokashi Living team

  5. If there are maggots in the bokashi bin, will the whole bin go bad? I noticed some when I emptied my kitchen container in today. I covered them with the bran powder and will seal it now for 2 weeks as it is full

    1. Hi Janet,

      Its likely that an opportunistic fly laid some eggs in the food waste prior to adding it to your bokashi bucket, or when you had the lid off your bokashi bucket. This can happen from time to time but don’t worry. As long as the bin smells sweet and pickly and there is no blue/green mold, then the bin won’t fail. In fact, the anaerobic and acidic environment inside the bokashi bucket will mean that they will die off pretty quickly (and add protein to your bokashi compost 😉 ).

      Throw an extra tablespoon or two of bokashi bran into the bokashi bucket to make sure that there are enough microbes to create an acidic environment.

      Some of the small maggots may escape when you drain the tea. The tea is still perfectly fine to be used; I just wouldn’t use it on house plants.

      Please comment here if you have any other questions.
      Happy bokashi’ing 🙂

  6. Hi Nicki,
    I am using homemade lactobacillus serum and sawdust for my bokashi. I finished a successful one and buried it. I was very happy with the outcome and it smelled really good. However on my other trials its smell is not as good as it used to be and there is a lot of gas coming out of the bin. I am especially concerned about the gas. Nearly all the conditions are same with the previous successful ones. I am becoming suspicious about my serum but the ph is around 4 when I checked it and the serum alone still smells goood. What could have gone wrong? Many thanks in advance for your advice.

    1. Hi Gunes,

      Thanks for the question and interesting to hear your experiments with bokashi composting. Without more information about your process for making and using the serum and sawdust it is hard to give a definite answer. However, my first thoughts would be that maybe the serum has been stored incorrectly. This is obviously a living ingredient and needs to be stored out of direct sunlight and within a few degrees of room temperature.

      The bokashi fermentation process should give off very little (if any) gas. Getting a lot of gas from your bin suggests that some putrification is happening. But its odd that it does not smell putrid?! Maybe the items in your bin are too big? Or maybe the serum has become less active?

      We would suggest checking on the way that the serum is stored and increasing the amount that you add to the bokashi bucket.
      Would love to hear how you get on.
      Thanks and happy bokashi’ing
      The folks at Bokashi Living

  7. Hi Nicki,

    Thank you very much for your quick response. I will make a fresh start with three different bins and check the variables. I will keep you informed as soon as i achieve a successfull one.

  8. Hello, i am using Bokashi Composting for my kitchen waste. I put aside my bokashi bin for 15 day for fermentation after it got full. I dont have a garden so i dumped the precompost in a plastic drum along with cocopeat. But now it is smelling really bad. How to do curing of precompost successfully if there is no garden to bury the contents.

    1. Hi Mrudula,

      Thanks for your comment (and FAQ). When using a bokashi soil factory be sure to add plenty of good quality garden soil. Also make sure to mix and chop the pre-compost really well. As your FAQ eluded to, it is also important to prevent excess moisture turning the soil factory bad.

      Happy composting,
      The Bokashi Living team

  9. Seems weird that mine was doing fine and smelling great at the point when the bucket was full, at which point I stopped adding, sealed it with saran wrap, put the lid back on and left it for two weeks. Then when I opened it it stank to high heaven.

    Is there something that can go wrong just at that last stage? Next time should I add a whack of the bran before that letting-it-sit stage?

    1. Agree, it is unusual for things to go wrong at this stage. It is most likely that the liquid (bokashi tea) built up in the bottom of the bucket and caused the bin to go bad.

      Ideas to try:
      1. Add a drainage plate, liquid reservoir and spigot to your bucket. Or consider investing in a ready-made bokashi bucket.
      2. Add more dry material to the bottom of your bucket to soak up the extra liquids.
      3. Avoid adding moist and/or juicy food waste to limit the amount of tea produced.

      Hope that helps. Feel free to ask any other questions you may have.

  10. Hi there,

    Just did our first bokashi and followed all the steps, but the smell was truly horrendous! Firstly, the drained liquid smelled like acidic vomit, and the bin itself pretty bad as well. When I emptied I noticed lots of white mould, which I understand is good, but surely it shouldn’t smell like this? We used the liquid rather than the grains, could this be the problem? It’s also been very hot so wondering if it’s just a temperature thing?

    1. No, the fermented food waste (bokashi pre-compost) should not smell like vomit. It should have a sweet, pickly smell, possibly with a slight yeasty odor too.

      As you say, white mold is a good sign but if the bokashi bucket smells rancid, then it suggests that the bokashi bucket has gone bad. Take a look at our troubleshooting blog post for common reasons why the bokashi bucket may have failed and how to prevent it happening in the future.

      I have not personally used the bokashi spray, but note that it has a much shorter shelf life than the bokashi bran (just 2-3 months). Make sure that you are using new bokashi spray. And make sure you are getting a good coverage each time you add it.

      Temperature could also be a problem. The bokashi microbes thrive around room temperature. At lower temperatures, the microbe activity will decline but at much higher temperatures the microbes can be destroyed. Try to keep your bokashi bucket and bokashi spray as close to room temperature as possible, and out of direct sunlight.

      Feel free to post any other questions you may have.
      Happy composting

  11. Hello! I am very new to Bokashi, I failed my first week and have green molds from bin. I have a few questions
    1) Is it safe to bury it in a garden compost (for a vegetable garden)?
    2) Will it make the soil toxic (d/t green mold)?
    3) If I make a bokashi soil generator, does it need to be airtight? what if it rains? I live in a studio without anywhere to put the bokashi soil generator except an open parking space.

    1. Hi, thanks for the questions. Tough to hear that your first bin failed. But don’t worry, most people quickly find a rhythm with their bokashi composting so don’t feel disheartened.

      1. Yes, the bokashi pre-compost is fine to bury in a vegetable garden. Just add a couple of generous handfuls of bokashi bran when you bury it. Bury it a bit deeper and leave it for a couple of weeks longer. It will break down eventually.

      2. No, it will not make the soil toxic. The life in your soil will break down all of the food waste, it will just take longer to break down the green molds. But the good life and good bacteria in your soil will take over in the end.

      3. No, the soil factory does not need to be airtight, though you should cover it to keep the rain out.

  12. Hi Bokashi gurus, I’m trying my first go at bokashi. I think I successfully made it through step 1 of filling my bokashi bucket and fermenting my food scraps. When done step 1, my bokashi had a kind of vinegary/pickled smell but I never did get any white mold. About 6 or 7 weeks ago I transferred to contents to a soil factory. I’m in a townhouse and don’t have access to much garden soil so I used bags of garden soil from the home centre to build my factory. My factory container is an old green waste bin so is tall and deep and fairly airtight. I had chopped my green waste very small when I added to the bokashi bin and as I built my soil factory I made several layers… first soil, then scraps and I was careful to mix the scraps with some soil as I built each layer. I then covered the whole thing with several inches of soil. I kept the bin in my garage away from sunlight and high temps. I just inspected it and now it has a not very nice, ‘kind of garbage dump’ smell. I had high hopes to be able to use the finished product to amend soil in my containers. Has it gone off or can I still save it? Thanks for your help!

    1. Were you able to add drainage holes to the bottom of your soil factory; we realise this is not always possible depending on where you are keeping the soil factory? Soil factories without drainage hole run the risk of becoming too damp and can create this ‘garbage dump’ smell.

      But do not worry, all is not lost. You have 2 options:
      1. Firstly you can mix through a couple of handfuls of bokashi bran and add another inch or two of soil to the top. Then wait for a couple more weeks.
      2. Alternatively (and this is likely the easier and preferred option), simply use this pre-compost/soil mix in the bottom of you containers. Empty the container, leaving an inch or so of original soil at the bottom. Add a generous layer of your bokashi soil factory contents and then top with a few inches of the original container soil. Repeat for all your containers. Save any extra soil to use for your next soil factory as this soil will have more life in it than the sterile bagged compost. Alternatively simply add your bokashi pre-compost directly to your containers next time you are refreshing them (

  13. Where to dispose of the failed batches? Municipal Garbage? Bury it anyways in the garden? That would surely attract rats. Thanks,

    1. Yes, you can dispose of it in the municipal garbage or bury it in your garden. If you are burying it in your garden, make sure to bury it deeper than usual and add a couple of extra handfuls of bokashi bran. It will break down eventually, but it will take quite a longer than usual.

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