Here is the bottom line: Without high-quality, high-diversity compost, you cannot brew high-quality, highly-diverse (biologically) tea.  That's it.  The compost you use in your tea is the most important factor.  There are several books on composting.  One of the best is: Field Guide to On-Farm Composting.  It is published by Natural Resource, Agriculture, and Engineering Service (NRAES). It is publication number NRAES-114.

So what is the big deal about composting?  You need to manage several things to produce really good compost instead of a pile of garbage.  These are:

Carbon-To-Nitrogen ration (C:N)                20:1 through 40:1
Moisture Content                                            40-65%
Oxygen                                                            Greater than 5%
Particle Size                                                    .5 to 2"
Porosity of Pile                                              Greater than 40%
Bulk Density (lbs./cu yd)                              800-1200
pH                                                                    5.5 to 9.0
Temperature                                                    110 to 150 during active composting. 

Table taken from NRAES-114, PAGE 8.

P.O Box 6741
Los Osos, CA 93402
(805) 534-9605

Cold Composting -- Experiments are under way with cold composting.  This is a process where the compost pile is inoculated with aerobic bacteria/fungi and kept at temperatures under 110 Degrees Fahrenheit.  Instead of heat killing the pathogens, the aerobes out-compete the pathogens for available food just as in tea.  Contact EW/SOE for guidelines if you wish to experiment with this kind of composting.  You will need to test while doing this to make sure you are actually controlling the pathogens found in manure you may be using.

EW/SOE has brewers and brewer designs from 2 gallons up to 225