Re: [compost_tea] withholding period

From: <soilfoodweb_at_aol.com>
Date: Sat, 13 Sep 2003 04:12:33 EDT

The concern about consuming CT comes form the compost used. If the compost
is not fully composted, which means it didn't pass through or touch worms
enough (vermi-compost), or the compost didn't reach 131 F for a full three days in
all parts (thermal compost, and it means ALL of the outside has to be turned
to the inside of the pile to reach temp for 3 days, minimum), then you have to
test the pile for human pathogens before use.

Of course, if you didn't put anything that would contain a human pathogen in
the pile, you are pretty safe that the compost won't have human pathogen
problems. So the composts that must be carefully dealt with are those contianing
manures or post-consumer waste materials. Human are great at contaminating
food with pathogens. So, with manure-based or human garbage-based compost,
there's a serious concern to make sure composting went correctly.

If you know the compost was fine, or even if you had minimal levels of E.
coli in the pile, the ACTIVELY AERATED tea brewing process will maintain the high
diversity of bacteria, fungi, and protozoa needed to compete with the
pathogens' ability to get food, have space, or obtain nutrients. Slow the growth and
competitive ability of these organisms down by letting the oxygen drop too
low, and now you can have growth of the human pathogens.

There's been some silliness about molasses CAUSING E. coli to grow, but what
seems to really be the problem there is that molasses at concentrations about
1% or higher results in such rapid growth of the bacteria that oxygen in the
liquid is used up, and the brew becomes anaerobic, letting E. coli win.

Some brews that we ran showed at 5% molasses, the fungi were able to
out-compete the bacteria, and reduced bacterial, and increased fungal growth occurred.

That has not been repeated by other people, so some other factor was also
operating in our trials at that concentration of molasses. More to learn. Need
to keep eyes open to figure out what allowed the KIS brewer to give these
results, where other brewers do not seem t o be able to give those results.

OK? Hope this helps -

Elaine Ingham
President, Soil Foodweb Inc.
www.soilfoodweb.com
SFI Oregon, USA
SFI Australia
SFI New York
SFI Europe
SFI New Zealand

"Hope is not a feeling. It is not the belief that things will turn out well,
but the conviction that what we are doing makes sense, no matter how things
turn out." -- Vaclav Havel, former President of the Czech Republic





Received on Sat Sep 13 2003 - 10:11:27 EDT

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