Mold in your bokashi bucket

We often get questions about mold in bokashi buckets. Mold can be a good sign. But it can also be a sign that things are going bad. It really depends on the color of the mold.

White mold in your bokashi bucket

White mold (mycelium) on bokashi food waste

If the mold is white then don’t panic! In fact, white mold is good, and is a sign of a successful bin.

The white mold may be white fluffy mycelium clouds, or smaller specks or strands of white on the surface of the food waste.

The white mold is actually a fungi and shows that the food waste is fermenting rather than putrefying. Fermentation is exactly what you want in your bokashi bucket. So, if you see white mold on your bokashi food waste, you can be confident that everything is going well in your bokashi bucket.

Note: White mold is often considered a sign that some air is getting in to your bokashi bucket. A completely airtight bokashi bucket typically shows no white mold.

Blue or green mold

Black, blue or green mold is a sure sign of a problem with your bokashi pre-compost. These darker colored molds are signs of rotting and putrefaction. These should not be present in bokashi composting.

Often times, dark mold is a sign that your bin has failed. When this happens, dispose of the contents of the bokashi bucket or bury them deeply in the garden. If burying, add a couple of handfuls of bran with the failed pre-compost and leave undisturbed for a few months. The failed pre-compost will eventually assimilate with the soil.

In some cases, if there is only a little blue, green or black mold, you may be able to recover the bucket. Add a couple of handfuls of bokashi bran to the small patch of dark mold, cover and close the lid. Check back in a day or two. The beneficial bokashi microbes may out compete the blue and green molds and get your bokashi bucket back on track.

If you see dark mold on your food waste, make sure to check our troubleshooting guide to help prevent it happening again.

Most commonly problems occur because the bokashi bucket is not completely airtight. Make sure your lid is tightly sealed, the composter is not cracked, and that the spigot is completely closed. Also, make sure that enough bran is being added to the food scraps. We recommend adding about 1 tablespoon of our premium bokashi bran for every 1″ layer of food scraps. More if you are adding hard to compost items such as meat, bones and dairy. Another common problem is using bran that is no longer viable. Bokashi bran needs to be fresh (less than 18 months old) and needs to be stored correctly (How to store bokashi bran). Bran that is old or stored improperly will have far fewer active bokashi microbes and be inefficient for bokashi composting.

Bokashi bucket with no mold

No mold in bokashi bucket

Often times, especially with a well sealed airtight bin, you may see no mold at all on your bokashi food waste. That is perfectly normal, and another sign of a healthy bin. The contents should still have the distinctive sweet, pickly smell of bokashi composting.

A successful bokashi bucket does not have to have white mold on it.

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

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10 thoughts on “Mold in your bokashi bucket

  1. Hello,
    I just started doing bokashi composting. I live alone so don’t collect much food waste each week to put in my bokashi bin, so I am concerned the scraps will start to mold BEFORE I even put in the bin. What do I do in the interim. Put in the freezer so it doesn’t decompose? I don’t want to ruin my compost before I even start.
    thank you

    1. You are correct to be concerned about the food waste going moldy before you add it to your bokashi bucket. Moldy food can cause the bokashi bucket to fail. But don’t worry, you have a couple of options. You can simply add the food waste that you have every day or two. There is no need to wait for a full inch layer before you add the food waste. If you are adding a thinner layer of food waste, you can also add a bit less of the bokashi bran. Alternatively, as you suggest, you can keep the food waste in the fridge until you have enough to add to the bokashi bucket.

  2. Hello, I am just trying bokashi the first time and I fermented the first basket successfully, including good smell. I prepared a soil factory on my balcony (as per your article) to finish the process using old soil from plants and some new soil from a garden center (do not have where to get a garden soil). One week later when I opened the soil factory to check, instead on the black soil I see white mold, covering about 90% of the surface. Is it Ok or have I done something wrong?
    Thank you

    1. White mold is a sign of healthy bokashi microbes. The white mold forms when the microbes are exposed to air, so it commonly occurs on top of soil factories. It is a sign that you have done everything right πŸ™‚

  3. You mentioned that it is normal to have mould in the soil factory. Once my soil factory is ready for some potting do i just remove the top mouldy area?

    1. The white mold can just be mixed in with the rest of the compost. The white mold is a sign of healthy bokashi microbe activity; you want to add as much of this to your garden as possible πŸ™‚

  4. Hello,
    My bokashi compost did very well, but after depositing into a bigger bin with some soil to over winter, I discovered green and blue mold after two weeks. I read that it might be possible to save, but wondering if this has to do with the amount of moisture I found in the bin?

    Would it be better to store outside for the winter and restart in the spring? We were -28 yesterday and today so things will definitely freeze.

    1. Hi Beth,

      Once your bokashi food waste is fully fermented and added to your soil it is less sensitive to low temperatures. The microbes will slow down and may go dormant in cold weather, but will recover as the temperatures rise. So your (very) cold temperatures will not have harmed your bokashi compost. The blue/green mold may have developed on pieces of bokashi’d food waste that were not fully mixed in with the soil.

      We recommend giving your bigger bin of soil and bokashi pre-compost a thorough mixing and chopping (either now, or when the soil is unfrozen and workable). Then add a few inches of fresh garden soil to the top and leave it to finish breaking down. Next time you add bokashi pre-compost make sure to mix and chop it thoroughly with the soil as you bury it. Large unmixed pieces take longer to be assimilated in to the soil.

      If you continue to notice some patches of blue/green mold after burying the bokashi pre-compost, then go back to the basics with your bokashi composting. Make sure that you are chopping your food waste small enough (ideally less than 1-2″), make sure that you are adding enough bokashi bran (around 1 tbsp per 1″ layer of food) and that you are leaving your waste to ferment for at least 2 weeks after adding the final layer of food waste and bran to your bokashi bin.

      Happy composting πŸ™‚

  5. I have a white mould which appears normal but also for the first time a bright orange mould! Is this ok for burying in the garden as I usually would the compost? I want to plant on it fairly quickly

    1. Hi,

      Thanks for the question. We don’t have any first hand experience of orange mold in a bokashi bucket! If there is only a small area and the rest of the bucket looks and smells as usual, then this bokashi pre-compost will be fine to bury. If you want to be able to plant on it fairly quickly, then make sure that you mix and chop it well when you bury it. The time spent mixing and chopping allows the soil web to get to the fermented food waste and break it down quickly.

      Happy composting πŸ™‚

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