C. 5. Compost Tea Standards

Desired levels of organisms (direct microscopy) in compost tea

• 10 to 150 or more µg active bacteria /ml compost tea
• 150 µg to 300 or more µg total bacteria /ml compost tea
  15,000 - 25,000 or more bacterial species (using molecular methods)
• 2 to 10 µg or more active fungi /ml compost tea
• 5 to 20 or more µg total fungal biomass/ml compost tea
  5,000 to 8,000 or more fungal species (using molecular methods)
• 2,000 or more protozoa
  1,000 or more flagellates
  1,000 or more amoebae
  10 – 30 ciliates. Higher numbers indicate anaerobic conditions resulting from organism in tea growing so fast that oxygen is consumed
• 2 to 10 BENEFICIAL nematodes/ ml (desired; typically lacking in tea)
  1 - 5 bacterial-feeders
  up to 5 fungal-feeders
  1 - 5 predatory nematodes (typically lacking in tea)
  No root-feeding nematodes
• Minimum of 10% active bacteria and fungi

With biology at or above these minimal ranges (more is better), this tea should result in improving foliar or soil life significantly, as long as pesticides, pollutants and dust are not a problem.

Application of a tea containing this set of organisms should result in a minimum of 65% of the leaf surfaces covered with bacterial biomass, and 5% with fungal biomass. In trial after trial, we have shown that with this minimum level of coverage, the leaf surface is protected, through a variety of mechanisms, from colonization by pathogenic organisms.

Compost Tea Standard Conditions

ome rumors flying out there suggest that someone is saying that there are no standard conditions for tea production, but in fact standard conditions are necessary in tea production.

In order to make consistent compost tea, the starting conditions must be t he same, and the same conditions must be maintained during the brewing.

We manage to routinely make teas with the same bacteria, fungal, protozoa and nematodes biomass and numbers present, time after time. But if you want something with a different set of organisms, or different levels of organisms, change the foods, the temperature of brewing, aeration, or water conditions. Maintaining the same conditions allow the same brew to be made over and over. Changing conditions allows a different tea to be made. Like making cake, or beer, biology responds to what you put into the starting mix and how you treat the material during the brewing, or cooking, process.

Standard conditions are:

1. room temperature water to begin,
2. no chlorine (aerate to de-gas)
3. neutral water (pH 6.5 to 7.5),
4. oxygen maintained above 6 ppm through the entire brewing cycle, and
5. good aerobic compost (per gram dry weight of compost) containing at least:

The list of papers specific to compost tea and compost have been summarized by Steve Diver, and are listed on the ATTRA website, www.ATTRA.org

Habitat requirements for beneficial bacteria and fungi required to prevent pests and pathogens

• Maintain 5.5 ppm O2 or higher during brewing cycle
• Pleasant Smell
• Increase in temperature of 1 to 10 F is normal
• Foam is typically sign of good bacterial metabolite development
• Maintain tea fully aerated as long as held before use

Testing Requirements

For new (untested) tea making machine:

• Compost quality (outlined above)
• Starting recipe of the tea
• Temperature, oxygen concentrations through the tea cycle
• Color of tea, foam, smell
• Chemistry and Pathogen testing must meet local standards (city, county, state, Federal).
• Organism assessments must be performed on three batches of tea
• Duration of the tests are 32 hours or until the growth of organisms in the tea is completed. This establishes the brewing cycle; extraction, growth, expected increase in organisms, duration of the tea cycle, when tea is ready to be used and whether the machine can hold tea for any length of time.

For existing machines with the above data available from the manufacturer:

• Type of tea maker used,
• Compost quality
• Starting recipe of the tea
• Temperature, oxygen concentration, and CO2 or O2 data through the cycle must be submitted for each of the first three batches of compost tea
• Chemistry and Pathogen testing must meet local standards (city, county, state, Federal).
• Initial three batches of tea must show three consistent sets of organisms produced at or above levels given above
• Once initial testing passed, each batch test each 3 months, or each set of different starting materials.

Sampling requirements for healthy foodweb assessment

• At end of desired brew cycle (depends on machine), measure temperature and CO2 or O2
• With the tea maker still circulating the tea, take at least 5 different 1 to 2 ounce or 30 to 60 ml samples and place them in a clean plastic 8 to 12 oz (100 to 500 ml) plastic bottle with sealable lid.
• Put the lid on the bottle, mix by shaking. If after mixing, the sample bottle is more than _ full, drain to halfway mark to allow airspace. The bottle should contain at least 125 ml (4 oz) of tea.
• Send overnight to SFI lab. Send with completely filled out sample submission form

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