What Is Bokashi and How Does It Work?

Bokashi is a Japanese composting method that ferments rather than decomposes organic material, using effective microorganisms (EM) carried in an inoculated bran or liquid. Unlike hot composting or a wormery, bokashi can process virtually all organic kitchen waste including cooked food, meat, fish, and dairy — materials that would cause problems in a conventional compost bin. It is compact, odourless when the bin is sealed, and produces a pre-composted material that can be buried in the garden where it decomposes quickly into the soil.

How the bokashi process works

Add kitchen waste to a sealed bokashi bucket in layers, sprinkling a small amount of bokashi bran between each layer. The bran contains lactobacillus and other beneficial microorganisms that ferment the material in anaerobic (oxygen-free) conditions. Keep the lid tightly closed between additions. A tap at the bottom of the bucket drains off bokashi liquid — a dilute liquid fertiliser that can be used on plants or poured down drains as a drain cleaner. After two to four weeks, the bucket is full and the fermentation is complete.

Using the fermented output

The fermented material from a bokashi bin is acidic and should not go directly onto plants — it needs a second processing stage. Bury it in trenches in the garden (dig a trench 30 cm deep, add the material, and cover with soil) where it decomposes within two to four weeks during the growing season. Alternatively, add it to a conventional compost heap where it accelerates decomposition of the surrounding material. The buried bokashi significantly enriches the soil with nutrients and microorganisms.

Is bokashi worth it?

Bokashi is particularly valuable for households with significant quantities of cooked food waste that cannot easily go into a standard compost bin. For a garden with a working compost heap and mostly vegetable peelings, the extra bran cost and two-stage processing may not be justified. As part of a system — bokashi bucket indoors for all kitchen waste, compost heap outdoors for garden waste — it creates a very complete zero-waste home composting solution.