Bokashi Composting: Step-by-Step Guide

Bokashi composting requires a specially designed bucket that you will likely need to buy. Though there are DIY versions out there, you'd need to be fairly handy to make one. The bokashi bucket should keep your food scraps elevated above your liquid and have a way to easily drain the tea via a spigot at the bottom. The whole thing needs to be totally self-contained and airtight so it won't smell or attract insects.

You can choose pretty much any size of bucket. Some people like to keep them on the countertop, where they blend in with other kitchen appliances, or next to the garbage can or in a pantry; in that case, you'd get a smaller one. Once you get the hang of it, if you decide to scale up, you might want to have two larger buckets going at the same time, maybe in a basement, garage, or utility room.

Besides the bucket, the other important component in this system is the inoculant, usually a combination of bran, molasses or other type of sugar, and effective micro-organisms (EM) made up of specialist bacteria (Lactobacilli) and yeasts (Saccharomyces) needed for the fermentation process. These bokashi bran bacteria convert some of the carbohydrates in your scraps to lactic acid through a homolactic fermentation process. This inoculant can be found online as bokashi bran.

1. Prepare Your Bokashi Bin

   Buy or make your bokashi bin. Some people use two bins so that one can be fermenting while the other one is being filled. Each bin will hold about 5 gallons and an average household will take about two weeks to fill it.

   Then, find the perfect spot for your bins. Since they do not smell, many people keep them indoors. If you want to place your bins outside, make sure they are in a shady spot. A warm-enough garage could also be a good option. Keep in mind that your bokashi bin can't be kept outside when temperatures drop below zero because that will kill the bacteria.

   After the fermentation process is done, you'll have material left over that you'll be able to compost or work directly into your garden soil.

2. Order Bokashi Bran

   Look for bokashi bran, a dry product that comes in bags. You will need to store it at room temperature and avoid any possibility of it freezing.

3. Load Up Your Bin

   Start adding food scraps to your bin. Consider chopping them up into 2-inch or smaller pieces, as this will help the chemical process move more quickly. You can add the food scraps as you produce them. When you open the bin, it will smell mostly like pickles or sauerkraut.

4. Add Bokashi Bran

   Add one or two tablespoons of bokashi bran for every inch of material you add to your bin. Err on the side of adding too much (you can never add too much bran, though you can definitely add too little). Smoosh the top of your layer of food waste and bokashi bran down as flat as you can—remember, this is an oxygen-free process, so while you are building up your bucket, keeping as much air out of the bottom layers as possible is the goal.

5. When Full, Let Ferment

   Once your 5-gallon bucket is full, keep it closed and untouched for at least two weeks. Some recommend letting it go a little longer, especially if you haven't chopped up your scraps so well. One week is the absolute minimum amount of time, but longer is better.

   You want to be sure not to let any oxygen into the bucket. This is an oxygen-free process, so avoid the temptation to peek. While you are waiting for this bucket to ferment, you can start another bucket.

6. Drain the Bokashi Tea

   Every 2-3 days during the 14-day fermentation period, drain the juice out of your bokashi fermentation system—this is where that spigot comes in handy.

   You can store this liquid or use it right away. For most plants, dilute 2-3 ounces of the bokashi tea per gallon of water and add to the soil. You can use it on houseplants as well as outdoor spaces. It won't attract pests and might even deter them.

7. Bury or Compost Your Leftovers

   You will be left with what is basically a bucket of fermented, or pickled, food once the 14-day fermentation process is complete. This is sometimes called pre-compost because it's already partially broken down. It can be added to your regular hot or cold compost and will break down very fast, compared to non-fermented materials. Since it's so acidic, it won't attract flies or bugs of any kind.

   You can feed it to worms in a vermiculture composting system. Just rinse the pre-compost and introduce it slowly to the worms so they can get used to it.

   You can also simply bury this waste in your garden directly (in a fallow bed, ideally) by digging a trench and filling it. Again, because of the acidity of the fermentation process, it won't be attractive to scavengers or bugs, and soil microbes will break it down in a couple of weeks.

   Rinse the bucket thoroughly before starting your next batch.

Frequently Asked Questions

Will bokashi tea by itself really help my plants grow?

Yes, the liquid product from bokashi fermentation has been shown to improve plant yields by improving the nitrogen in the soil and providing an ideal carbon/nitrogen balance. It must be diluted before use, though.

How do you know if your bokashi compost isn't working right?

It's fine if there's some white mold in the bin, but black, blue, or green molds or a foul smell indicate that something has gone wrong.

Should my fermented bucket look the same as when I added the food waste?

Yes, it will look very similar and food pieces will be identifiable—since this is a fermentation process, not a composting one. However, there have been significant chemical changes that might not be obvious to the naked eye which make this material different post-fermentation.