This should be a very interesting article for those practicing bokashi composting at home. If you aren’t familiar with bokashi composting, we have an excellent bokashi composting overview here. Most people doing bokashi composting get hung up on bokashi bran. Places selling bokashi supplies will always sell bokashi bran to go with the bin. It tends to be expensive, and you have to keep buying it! Fortunately, you can make your own bran very easily.
However this is where people get hung up again. Nearly all bokashi bran recipes call for using “wheat bran” as the main ingredient. If you don’t live in the states, this can be hard to find and quite expensive. However we are fortunate again, because you don’t actually have to use wheat, or any other type of bran! To know why, go back to the principles of bokashi bran.
What is Bokashi Bran?
When you are making bokashi compost, to make sure the correct organisms proliferate, you use bokashi bran! This bran, saturated with the correct mix of organisms, is applied when you add more materials to the bin. This ensures that as you add materials, you also add more “good” microbes to keep the system on track, and prevent bad anaerobes from taking over. So what is bokashi bran? It is simply a mixture, normally kinda dry and crumbly when purchased from the store, that contains beneficial microbes. With this definition, we’ve gained quite a bit of freedom from the restrictive descriptions typically used for bokashi bran. Now that we know what bokashi bran is (based on defining what it is used for), let’s look at how to make it.
So bokashi bran in this context is simply a substrate that contains a live (or dormant at least) culture of microbes ready to ferment your kitchen scraps. To start with you will need the base substrate. This can be any carbon-rich medium. I have seen newspapers used, sawdust, all types of bran, etc. Let’s look at a list of possible substrates:
- Coffee grounds
- Wood chips or sawdust
- Bran (wheat, barley, oat, rice, etc varieties)
- Rice hulls
- Groundnut cake (residue left after oil is extracted from nuts)
- Coco coir (coco peat)
- Peat moss
You get the idea. Anything with a decent amount of carbon in it, that won’t physically or chemically change too much during fermentation. You want a substrate that the organisms can grow and persist on.
Note: In this article I want to make bokashi bran as simple and flexible as possible. Not all substrate is the same. A nice rich substrate like bran or groundnut cake is more ideal than something completely inert like biochar. For example wheat gluten (present in wheat bran) produces very high levels of gluconic acid upon fermentation, which is an excellent organic acid for your garden and animals. But it’s still possible to make bran with any of the above, so go nuts!
Principles of Bokashi Bran
Let’s look at the 3 basic principles of bokashi bran: correct organisms, good nutrients, and proper moisture level. As long as you get these 3 factors covered, you are on the right track to making your own bokashi bran at home.
Bokashi composting relies on a diverse group of anaerobic (non-oxygen breathing) organisms to ferment the materials in a sealed, oxygen-free environment. Certain organisms are required for a healthy bokashi system to work, most notably Lactobacillus (though many others are beneficial, like Actinomyces, Streptococcus, Staphylococcus, Azotobacter, Azospirillum, Pseudomonas, and more). Ideally you can include many anaerobic organisms, but at the very least you need Lactobacillus species, the main workhorses in fermentation.
To ensure you have a good group of organisms, start with a culture. You can make your own mix of Beneficial Indigenous Microorganisms (BIM), or you can follow our recipe on how to make lactobacillus. This is the most ideal way to begin, because you start with a good healthy culture of microbes.
If you can’t make a full serum like lacto or BIM, at the very least leave a nutrient broth out for a few days to get it infected with your local microbes. Any complex carbohydrate will do (e.g. rice wash from the lacto recipe). Then use that broth to inoculate the substrate you’re using for bran.
Nutrients for Fermentation
For the beneficial bacteria to dominate, you need to provide a simple carbohydrate source. This basic source of energy allows the beneficial bacteria to quickly multiply and outcompete other microbes. Ultimately they produce acids and other compounds that inhibit growth of other organisms like fungi.
So any simple carbohydrate will work – sugars like molasses (this is the best option), brown/white sugar, jaggery, syrup, honey (not ideal since it has anti-microbial properties), etc – think sweet.
Correct Moisture Level
Bacteria need moisture to multiply. So you need to provide them with a nice moist environment. Preferably 60% moisture level or higher. If your substrate is dry, add water to bring up the moisture. If your substrate is already wet, you don’t need to add much water (while you can’t really add too much water, just avoid making a wet goopy mess if you can, haha).
Making Your Own Bokashi Bran
Using the ingredients above, you can make your own bokashi bran very easily at home. Here is the basic recipe:
- Combine 3 ingredients in this ratio:
- 1 part substrate
- 1/3rd part sugar
- 1/20th part microbe inoculant (max)
- Water until at least 60% moisture level
That’s it. Combine your ingredients and seal it up to make sure it stays anaerobic while it ferments.
How to Use Bokashi Bran
You can use bokashi bran in the garden directly, but it is more commonly used to inoculate batches of bokashi – kitchen scraps, compost, animal feed, or whatever type of bokashi you are making.
Used for Bokashi Composting
To use bokashi bran in your bokashi bin, mix it with the ingredients you will ferment. This is done in layers sometimes, as you can see in this tower of finished bokashi compost about to be mixed into my traditional compost pile:
Or you can mix up all the ingredients together, as you can see in this animal feed bokashi I made for the dog/roaches:
How Much Bokashi Bran to Use?? This really depends on what you are fermenting. If you are bokashi composting biologically rich stuff like aging meats and dairy, compost, manure (you have to be very careful with this one, not recommended for beginners), you would use more bran relative to what you are bokashi composting. For less microbe rich items such as vegetables, fruits, nuts, berries and fresh meat, you can use less bran. Also, the amount of bran you need depends on the quality of your bokashi bran, the richness and diversity of healthy microbial populations. You can see it’s a little complex. Just use 50% bokashi bran to start with if you’re using homemade bran. You can ease off from there as you get more comfortable.
Applied Directly to Garden
To apply directly to the garden, bury the bran at least a few inches deep in the soil, where it will quickly decompose (assuming it has some nutrients in it and isn’t inert, like biochar).
Applied in Compost Tea
You can also use bokashi bran in Compost Tea. You can add to your compost tea at 1/2 tbsp per gallon (a bit less than 1 tsp per Liter) at the start of the brewing cycle. You can use a bit more if you are brewing compost tea using a suspended bag method.
Applied as a Traditional Composting Aid
If you have a compost pile, especially if it got too wet, too compacted, or other anaerobic microbe favoring condition, bokashi bran can be an excellent addition to help keep the anaerobes healthy and in balance. Mix your bran into you compost pile in the areas you feel are at risk of developing anaerobic populations of microbes.
Composting Your Bokashi Bran
Composting your bokashi bran can be an excellent way to quickly break it down into a soil and plant-ready form. For example you can turn coffee grounds into bokashi bran, and they will be fermented coffee grounds. Their nutrients will be broken down a bit but not fully. To really liberate all the nutritional content of the coffee grounds, you would want to compost them before adding to your planter beds.
Bokashi Bran Summary
Now you know all about bokashi bran! Particularly, the basic principles of making bokashi bran at home. Since we have the basics, we can make bokashi bran no matter where we live, using ingredients that are extremely cheap and available. For example, Starbucks coffee chains gives out their used coffee grounds for free to anyone interested. Therefore, in cities like Manila, Philippines, you can pick up bokashi bran starter anywhere you have a starbucks store. For free! In the provinces here in the Philippines, there are other potential substrates available: rice bran (best), rice straw, coco coir, rice hulls, etc. Think about equivalent products where you live – agricultural byproducts make great gardening supplies, and bokashi bran is no exception.