Subject: Re: Proper compost

From: Elaine Ingham <[email-masked]>
Date: Tue, 5 Nov 2002 19:51:55 EST

Hi Roberto -

I am speaking from the USDA organic program point of view.  As Elliot Coleman
just pointed out to me (and he's right), the USDA really pushes thermal
composting.  There are other ways to arrive at the same E. coli-free
conditions, such as cold-composting methods.  At least worm compost has been
recognized this time around in the USDA regs.  That is a good addition.  But
there are other composting methods the USDA still left out.

>From a food safety point-of-view, compost needs to be E. coli free.  For
compost tea purposes, compost needs to be E. coli free.

As I've said before, E. coli is an indicator of the presence of other human
pathogens.  If E. coli is not present, most likely the human pathogens are
not present either, because the human pathogens, like Salmonella, Shigella,
Yersinia and Pasteurella have similar requirements for growth and survival as
E .coli.  If E. coli is present, sooner or later, you will have a human
pathogen present, and the likelihood for disease significant.

The question previously was whether properly composted material would contain
E. coli.  For thermal compost, if the growth of the organisms in the compost
raises the temperature to high enough levels, for long enough, under aerobic
conditions, then E. coli will not remain.  Simple.  How do you document
compost quality?  Testing.

Many people do not understand that the bacteria and fungi growing in organic
matter raise the temperature.  If all you do is physically heat compost, you
don't get the same reduction in E. coli.  This is a biological process.
Competition with aerobic bacteria and fungi, inhibition by other bacteria and
fungi, and consumption of disease-organisms by protozoa and nematodes are all
part of the process of making good compost, getting rid of the pathogens.

If you just steam heat organic matter, you don't get the same benefits of the
growth of the competitive, inhibitory and consuming interactions that happen
when the full food web is present.

So, to document that compost has been properly composted, you have to do the
testing.  But once you know that your mix of starting materials, the
temperatures and the turning that result in a good compost, then you just
have to monitor starting materials and temperature.  Check your end-product
now and again for biology and chemistry.

The thermal method pushed by the current USDA-NOP regs is hot and fast, and
can make "finished" compost in 6 to 8 weeks.  But not everyone wants to do
that.

Can't you make good compost in 5 months without high heat?  Yes.  But that
approach is not included in the NOP regs.

Does that mean long-term, cool compost isn't compost?  No.

How do you know if quality compost has been produced?  Organisms.  Chemistry.
 No E. coli, and all the good guys.

Once you have the process worked out, and can show it works every time, then
you just track temperature.  Do we have the longer process worked out?  We're
working on it.  Will E. coli be removed everytime?  So far so good.  What are
the important components?  The right starting materials, aeration and the
correct organisms.  Turning is not required, if you make the pile right.

This is the approach that Edna wants.  Can we get it certified organic?

If you make your own compost, and you mess up, and you get sick, you won't
sue yourself.  If you sell to other people, and they get sick, you better get
ready to lose your shirt, cause those folks are going to have your hide.

So, the regs really are for people who sell products to other people.  If you
aren't selling things, do you need the USDA regs?

Elaine Ingham
President, Soil Foodweb Inc.
www.soilfoodweb.com

---

From: Roberto Verzola <[email-masked]>
Date: Thu, 7 Nov 2002 12:25:05 +0800

Hello Elaine. Thank you for your excellent explanations on E.coli
and compost teas. I still have a question about your point below:

> From a food safety point-of-view, compost needs to be E. coli free. For compost tea purposes,
> compost needs to be E. coli free.
>
> As I've said before, E. coli is an indicator of the presence of other human pathogens. If E. coli is
> not present, most likely the human pathogens are not present either, because the human pathogens,
> like Salmonella, Shigella, Yersinia and Pasteurella have similar requirements for growth and
> survival as E .coli. If E. coli is present, sooner or later, you will have a human pathogen present,
> and the likelihood for disease significant.

It seems to me that to require E.coli testing of compost for it to be
considered organic sets an even *higher* safety standard than
testing for the presence of pathogens themselves (like O157:H7,
Salmonella, etc.). As you said, E.coli is simply an indicator, not a
pathogen itself (except a few strains), and that it simply indicates
conditions favorable to the emergence/growth of pathogens. So,
this standard disqualifies from organic certification a compost, not
because it contains pathogens, but because its contains conditions
similar to those which may be favorable to pathogens. This seems
to be a more restrictive standard.

Is this an accurate interpretation of the requirement for E.coli
testing of organic compost?

Roberto Verzola
Philippines

.