What is compost tea?
Compost tea brewers
DIY compost tea and extract
Available at Rincon-Vitova aka Bug Farm
What is Compost Tea?
What is Compost Tea – There are lots of ways to extract microbes from various organic materials such as manures and composts. What we’re talking about here is a process that strips fungi, bacteria, protozoans, nematodes and other small living things from high quality, finished composts. Finished thermal composts are those that have gone through high temperature, aerobic processing (turned at least weekly) that suppresses or kills pathogenic organisms, seeds, etc.. Mature worm composts are also excellent sources. You need to do some reading before you decide which type of tea will work best on your farm or garden.
The extraction process gently separates organisms from the compost through agitation and, by the addition of various foods, grows bacteria and fungi to make either fungal dominated, bacteria dominated, or balanced tea.
Bacterial ingredients used in teas include bacterial compost, and foods such as molasses, fruit juices, fruit pulp, fish emulsion and others. Fish Emulsion and Fish Hydrolase are two very different foods. Emulsion, ground up fish, is relished by bacteria while Fish Hydrolase, changed by enzymes, is the best fungal food I have found.
Fungus producing ingredients include fungal compost (mature but undisturbed for a week or more) and foods such as fish hydrolase, yucca or aloe vera extracts containing saponin.
Pre-treating – I have found it necessary to pre-treat my composts with Fish Emulsion (2 oz fish/20 oz. moistened compost) in a plastic tub with perforated lid. Hold for 5 days at room temperature. Long, thick strands of fungi should appear.
Water used to extract and grow microorganisms in these teas, water must be free of contaminants and Chlorine/Chloramines often used in municipal water treatment. Chlorine is easily removed by aeration, Chloramines must be removed using treatments sold at a pet supply store for fish tanks. Water must be aerated for fifteen minutes prior to adding compost materials.
High Oxygen content is critical to producing disease free compost teas and any steps taken from start to application should keep this in mind. A completed tea is alive with organisms that grow in Oxygen rich solutions and will quickly use up dissolved Oxygen once the aeration stops at the finish of the brewing cycle. Beneficial organisms will go dormant and any remaining dormant disease organisms that like anaerobic conditions will start to grow. For that reason aerobic teas must be used within hours, not days. After just three hours the quality of a tea deteriorates.
Uses for Compost Teas
There are two general categories for the benefits of applying compost teas.
Foliar application – Leaf pathogens that find their way on to leaf surfaces do not live alone, there are many other organisms that have blown onto or splashed upon the leaves. Bacterial dominated teas, when applied to leaf surfaces, compete with fungal organisms for space and nutrients. A quality tea may also contain organisms that are antagonistic and can suppress the ability of a pathogen to infect a leaf. Thus compost teas are applied to create a living foodweb that suppresses diseases such as downy mildew, bacterial spots and others.
Soil applications- are useful to restore active biological soil process that may have been damaged through the application of herbicides or fungicides or lack of organic matter. A compost tea high in fungal and bacterial biomass will add organisms for decomposing organic materials and may include a variety of species that protect roots from infection in the same fashion as on leaf surfaces. The organisms in tea can colonize roots and suppress disease infection.
Resources – If you consider making compost tea please visit www.soilfoodweb.com to see the current research and methods for making and using tea extracts.
The handbook, “Compost Tea Brewing Manual by Dr. Elaine Ingham” is a great resource for understand the complicated process that I have only outlined here. Soil Foodweb, Inc. is located at 1750 SW 3rd St C, Corvallis, OR 97333 Phone: (541) 752-5066
Also visit the NCAT web page http://www.attra.org/attra-pub/compost-tea-notes.html for links and further information.
By David Loring Dietrick Institute December, 2002
Compost Tea Basic Recipe
A basic tea recipe would be as follows, with the understanding that if larger or smaller quantities of water are used, change the amounts of additives relative to the amount of water.
a. 25 gallons of water, aerated to remove chlorine, add two teaspoons of a humic acid solution (preferably humic acid extracted from your own compost).
b. 1 to 2 tablespoons of humic acid diluted in 2 cups of water BEFORE adding to the compost tea water OR 1 to 2 tablespoons of fish hydrolysate (pre-diluted to neutralize the acid preservative according to the label on the container).
c. 1/2 cup of kelp mixed in 5 cups of water BEFORE addition to the compost tea
d. 5 pounds of good aerobic (good smelling, like deep forest soil) compost with excellent bacteria, fungi, protozoa in the compost.
Using a microscope, assess the compost: Using a 1:5 dilution of compost, 400X total magnification, there should be a MINIMUM of thousands of bacteria in each field of view, 1 strand of fungal hyphae in each 5 fields, 1 flagellate or amoebae in each 5 to 10 fields of view and 1 beneficial nematode per drop.
Additional foods if needed to improve fungi: 1 cup steel cut oats, or bran flour, or shrimp shells (no protein on the shells!) put in the compost bag with the compost Note: Rincon-Vitova has Bug Bits, dried insects available for use as a chitin source.
Replace humic acids with the same amount of fish hydrolysate if the plants need a nitrogen boost NO MOLASSES!!!!!!!!
1. Place the compost (please test so you know the compost contains the organisms needed as indicated above) in the compost bag (0.5 to 1 pound per 5 gallons of water)
2. Briskly massage the bag for 30 seconds to a minute
3. Check the tea to make sure it has the organisms needed.
4. If not enough organisms, then extract another 0.5 to 1 pound, repeat if necessary until organisms reach minimum or desired levels.
6. If the compost you are using has good sets of organisms in it, perform the procedure above.
7. But if you do not know if your compost is good or not, then add foods (humic acid or fish hydrolysate, or steel ground oats, or bran or.....whatever fungal food desired) to the compost 3 to 7 days before extracting (good air flow around the compost, don't let it get stinky).
Compost Tea Machines
Notes on producers and machines
Note: this list is dated, we are in the process of updating it. Send sugestions to firstname.lastname@example.org
EPM (Eugene Precious Metals) www.composttea.com - manufactures compost tea brewers and vermicomposting systems. Excellent extraction of microbes from compost. Uses a centrifugal pump, 100 gallon ($3,500) and 500 gallon. PO Box 1295 Cottage Grove, OR 97424 541 767-2747
KIS brewers www.simplici-tea.com – 5 gallon ($129) and 25 gallon Good extraction and easy to clean
Alaska Giant www.alaskagiant.com – 1 gallon ($40) and 5 gallon ($80), good extraction, uses soaker hose for aeration, nylon stocking for tea bag.
Earthworks www.soilfirst.com – 35 gallon ($1,500) and 85 gallon. Excellent extraction! Uses a tube diffuser and bag with large mesh for tea bag.
Ground Up - 50 gallon and larger, PVC tube with screen on bottom end and side that contains compost, air bubbles up through it.
Hendrikus Schraven www.hendrikusorganics.com - has been applying, innovating and researching with compost tea since the first brewers were available. Through his companies, he sells GSI compost tea brewers, HSO catalyst & compost mix for brewers, organic fertilizers and patent pending soils, and offers natural solutions and educational seminars to effectively respond to many of the environmental problems experienced in landscape, construction, erosion control, agriculture, turf and land development.
Growing Solutions www.growingsolutions.com – 25 gallon ($1,300) 100 gallon ($5,000) and 500 gallon ($12,000) Get bubbler for compost basket.
SoilSoup, Inc. www.soilsoup.com – doesn’t extract fungi. Need to use a non-woven mesh bag to get better extraction. Nutrient mix may suppress fungal growth in tea. 9792 Edmonds Way #247, Edmonds, Washington 98020 877-711-7687
Sustainable Works James Sotillo 631-474-5309 JAMSOT@aol.com International Compara International, Holland, www.compara.nl
Compost Tea Company, New Zealand www.compost-tea.com.au Compost Solutions, Australia
Soil Food Web – a resource for information on soil microbes, compost, and compost tea www.soilfoodweb.com
BBC Labs – information on compost tea www.bbc-labs.com
Compost Tea Extractors
-by David Loring
There are a half-dozen companies manufacturing compost tea machines, here are a few. Visit or call Soil Foodweb, Inc. www.soilfoodweb.com (541) 752-5066 for more information. Performance Standards These extractors have to basically do two things, aerate the solution to grow beneficial organisms (bacteria may increase hundreds of times given ample foods, fungi might increase ten times) and gently separate the organisms from the compost material held in the bag or other basket within the machine. My machine uses the bubbling action of an air diffuser located in the tank bottom to agitate a basket holding the composts that hangs from the top of the tank. The machine should also be easy to clean, including any piping, as unwanted bacterial films can develop. Don’t skimp on the air pump. When adding sugars for bacterial growth it is possible the explosion of bacteria will use up all available oxygen, especially 12-16 hours after the start. Air temperatures of 80 or 90 ºF can also increase growth rates that will use up oxygen, be careful adding sugars when temperatures are above 75-80*F. See the Compost Tea Brewing Manual for guidelines. In my experience there is never a need for more than 16 oz. of sugars in 50 gallons and adding only two ounces has generated the needed bacteria in my brewer when making a 25 gallon brew with 4 oz. fish hydrolysate also added.
Available at Rincon-Vitova
aka the Bug Farm
We are now brewing activly aerated compost tea at the Bug Farm on Monday to be available on Tuesday and Wednesday until the batch is used up. What ever is not sold will be used to enhace the Bug Farm food forest.
$9 per gallon for 1-4 gallon
$8 per gallon if you bring your own bottle/container (BYOB)
$7 per gallon for 5+ gallon
$6 per gallon for 5+ gallon if you bring your own bottle/container (BYOB)
We can take orders and you can call to check to see how much is available. Any orders not picked up by Wednesday 5 pm will be used on the bug Farm.
Our recipe for 25 gallon brewer is
2 Tablespoons Humic Acid
2 Tablespoons Molasses
2 Cups Worm Castings
1 Scoop Seaweed Powder
¼ Cup Ground Fly Pupae
Compost to Fill Tea Cylinder
Fill aerator with water and plug in; this will turn it on. Add humic acid first to dechlorinate the water. Add ingredients and cylinder with compost. Brew for 24 hours.
We can consider special brews and batches on other days, depending on having skilled labor available.
We have a 5 gallon brewer, 25 gallon Growing Solutions brewer, and an 150 gallon modified IBC tote
Rincon-Vitova Insectaries aka Bug Farm
108 Orchard Dr
Ventura, CA 93001