Posts Tagged ‘getting the pH low’

Bokashi. Not exactly composting. More like ensilaging.

April 21, 2010

[start quote] 
[cab] (…) Bokashi, as it has come to mean (…), is not a composting process. At all. It doesn’t make compost, but it does convert material that can’t be composted because it’ll go rancid or attract beasties into something that you can bury and ignore, and it also produces a nutritious liquid plant food. 

But the magical ‘effective microorganisms’ of which the sales pitch would have you believe are, in my view, rather spurious. 
The best results I’ve obtained have been by taking a fresh load (a little kitchen composter pot sized amount) of mixed kitchen waste, mixing in a tablespoon of glucose from a health food shop, and some Lactobacillus bacteria powder, of the type that you get from a health food shop (and which a home salami maker may have lurking in the fridge!). Mix up, put in a tightly sealed filled plastic container (a bokashi composter) with a tap on the bottom, and leave it for three weeks. 
When it works (which has been all but twice) you’ve basically got a bacterial de-proteination of the waste. Or, in other words, the Lactobacillus bacteria have gone nuts, eaten the glucose, and then gone looking for more goodies. The pH has dropped to a point where much of the protein has lysed out of the food waste and is sitting in the liquid (tap that off as plant food, needs diluting a lot of course), and the solid matter smells just a little unpleasantly sweet. Bury the waste in a corner of the allotment somewhere and ignore it. It’ll rot down, and worms will eat it. 
When it doesn’t work, it goes rank and horrid and you’ll need a strong stomach to deal with it. 
Using the bokashi ‘bran’ has been no more or less successful than a spoonfull of bacteria powder and some glucose. 
I conclude, therefore, that the process (at least with the waste we’ve been producing!) is very much akin to ensilaging.
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Date: Jan 27, 10    

Simply kickstarting the composting process.

April 20, 2010

[start quote] So, this Bokashi thing. 
It works well for starting off the composting process on anything you wouldn’t normally be able to compost, but the hype about the ‘effective microorganisms’ doesn’t convince me. Works very well (…) to start off the composting process for such things as meat, fish, cooked waste, etc; the pH falls to the point where proteins dissolve out as a rich liquour that makes a decent plant food supplement, the remaining material isn’t pleasant to smell but it isn’t totally sickening, and it breaks down at a reasonable speed in compost or just buried. [end quote] [cab: Not an expert. An informed dabbler perhaps.] Jul 01, 09          Source:

Those magic EMs are simply ensilaging.

April 19, 2010

Apr 29, 08 
[start quote]  [cab] (…) a simple ensilaging process for cooked food will be better and easier to control, [in] that the ensilaged, low pH waste will have most of the protein in it dribble out simply in the liquor, making for a handy high nitrogen plant feed, and that the ensilaged food waste should degrade marvellously when buried. It would be an easier approach, if it works.  [[It does.]]

Question:   What would an ensilaging process be – simple or otherwise?
Answer:   [cab] Crudely, in this instance it would mean selecting an appropriate lactic acid producing bacteria and giving it a carbon source it can use (probably glucose, although I’m sure it would do fine on ordinary sugar). It uses the sugar and other nutrients from the mix, outcompeting the other bacteria quite readily in this environment as long as you keep it close to anaerobic. The production of lactic acid eventually drops the pH to a point where the bacteria stop doing a great deal and not a lot else can grow either, and at a low pH most of the available protein in the waste will be lysed out. The remaining solid matter should be a bit spongier, and far more readily degraded by organisms in the soil such as assorted fungi and actinomycete bacteria, i.e. it’ll rot down pretty quickly and not fester with nasty smelly bacteria. [end quote]  
Date: Apr 29, 08