We've bought a house and found half a large tub of bokashi bran in the basement. This puzzled us a while as we'd never heard of the process, but a little Googling enlightened us. We've also got some bins, also left by the previous owners so we're interested in giving it a go.

We've no idea how old the kit is. Given the state of the bins (found under an archaeological layer of rubbish) and the wormery (well past it and the wooden lid rotted) I'd say it's probably been some years since any composting method was tried here.

Does the bran expire? It's been kept in cool dry conditions in a reasonable tub with a lid (loosely) on.


Estimates of the shelf life of Bokashi vary from 1 year to more than 5 years.

In any case the color of the bran should be light brown, optionally with some white patches, and have a slightly sweet smell. Also, it needs to be stored dry, cool and out of sunlight. If it has been exposed to sunlight (UV) the microorganisms in the bran may have died and the bran doesn't work anymore.


We give our bokashi bran a 1 year shelf life but it will typically survive much longer than that. As long as the bran is sealed and dried, kept out of direct sun and not allowed to freeze then it should last much longer. When the bran is kept sealed the bacteria are dormant.

If you are not sure, you can test a small batch. Get some food scraps, add some bran and seal in a container or bag. Leave to sit for up to two weeks. If the see white mould starting to form and/or smell a sweet, pickled smell then the bran is still fine. If you see blue/green mould and/or a putrid rotting smell, then the bran no longer has active EM bacteria and you will need to buy some fresh bran. The out-of-date bran is fine to be added to your compost pile or buried in your garden.

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