Bokashi composting is a little different from other methods as it is actually a fermentation system. In fact, the word Bokashi is Japanese for “fermented organic matter”. The end result is also different from the compost you would get from a hot, cold, or worm (worm compost) system. Instead of a dark brown, earth-like material, you get a nutrient-rich liquid called “bokashi tea”.

One of the biggest differences between Bokashi composting, or fermentation, and other types of composting is that it works anaerobically (without oxygen). In hot, cold, and worm composting, oxygen is incredibly important to ensure proper degradation of the material. This difference means that Bokashi composting also produces less CO2 than other types of composting, a clear benefit.

And since it’s a fermentation process, you can put more materials in your compost bin. In addition to the vegetable and fruit scraps, eggshells, tea and coffee grounds, you can also add fat, dairy products, meat and even bones to a Bokashi system. It also works much faster than any other type of composting, with the entire process taking 2-3 weeks.

Since Bokashi is a closed system, you need a specially developed bucket that collects the liquid fertilizer on the ground separately from the solid matter. These systems usually have a tap so you can drain the bokashi tea.

One disadvantage of the Bokashi system is that after the tea has fermented and drained, material is left over from your leftovers. This material would then have to be added to normal hot or cold compost or otherwise disposed of in order to complete the degradation process. You also won’t be able to compost large amounts of garden waste with a Bokashi system – it’s just for food waste.

Why composting is good for the planet

The hassle of bokashi composting has a few benefits beyond making a nutritious plant food from your leftover food.

With 30% of garbage made up of leftover food and garden waste, composting saves landfill space and reduces the greenhouse gas methane (methane is created when food waste breaks down in the oxygen-free environment of a typical landfill).

Although the Bokashi system is also anaerobic, due to the specific chemistry of homolactic fermentation, no methane is produced at all.

What can Bokashi compost and what not?

Bokashi composting – since it is actually based on fermentation – can contain more types of food waste than composting systems you may be familiar with. In addition to the typical fruit and vegetable leftovers, you can throw bones, meat, fat and dairy products into the Bokashi bucket.

However, since it is a smaller system designed only for food waste, you cannot compost large amounts of garden waste in a Bokashi system like you would with cold or hot composting. It is actually important to have a high amount of carbohydrates for a Bokashi system to work well, so garden waste would also affect the balance between carbohydrates and other materials that the bacteria love to eat.

While you can include some materials that would be excluded from normal home composting, there are a few things that you cannot compost with Bokashi. Small amounts of oil are fine, but don’t throw in the expired bottle of olive oil (or any other oil). Liquid is generally not good for the bokashi system, so don’t pour the quarter cup of tea in either.

Avoid adding any product or meat that is already very rotten. You should also not add any green or black mold waste (white or yellow mold, which is common on bread and cheese, is fine). Rotten food and dark mold have organisms that could actually work against the bacteria that do the hard work in a Bokashi system.

What you can compost Bokashi

  • Fruits and vegetables, cooked or raw
  • Eggshells
  • Coffee grounds and loose tea
  • Cooked food and leftovers (do not put warm food in, wait until it is room temperature or colder)
  • Beans, lentils, hummus, bean dips
  • Nuts and seeds
  • Pruning
  • Meat, fish and bones from these animals
  • Dairy products or foods with milk in them
  • Fermented and canned foods
  • Oyster, clam and shrimp shells