Compost tea is a way to take many of the beneficial organisms out of the compost and make a watery brew. The brew is then put on the leaves and stems of your plants and helps them grow better.
The tea is brewed by letting the compost sit in the water for 12-124hrs. There are all sorts of ways to make the tea and there several machines that can aid in the making of this beneficial product. You can use a starter to help feed the organisms as well.
According to Winkipedia, http://en.wikipedia.org/wiki/Compost_tea There are two types of compost teas.
anaerobic compost teas
"These consist of controlled compost extracts made by adding finished, properly prepared compost to water and stirring the mix for 1 – 14 days. This process encourages the loosening of microbes adhering to compost and soil particles so they are transferred into the water itself. The notion that compost tea is a "brew" process is of only recent origin in the USA. Traditional compost tea (called compost extracts) developed in Europe and especially in Germany by microbial scientists from the late 1970s on, did not employ significant technological support to prepare solutions of compost with microbial counts as high as 1011 per ml. The mixing, or active aeration, was required after the introduction in the USA of molasses, sugars and other highly fermentable agents created fermenting, anaerobic conditions; as a direct result, it became necessary to take extra steps to maintain compost teas in an aerobic condition, to be safe and non-odorous. If the tea is properly made, it is a mixed concentrate of facultative and aerobic microbes, and presumed non-harmful. The US National Organic Program has strict guidelines on use of compost teas in USDA certified organic farming; research evaluated by a Tea Task Force did not support the idea that active vs non-active teas had any differences in terms of microbial hygiene, and therefore the need to protect the safety of organic consumers and the integrity of organic farming became necessary. For example, E. coli testing of compost extracts is strongly recommended and may be required under NOP; the levels should be less than 126 cfu ml-1.
Traditional European formula: Steep 1 part compost in 3 : 9 parts water, with optional additions of a handful of basalt-meal or granite-dust and seaweed powder, and stand at room temperature ( 20 - 25C°) for 3 – 24 days, with frequent stirring. Sieve through cheesecloth or a fine mesh screen.
Aerobic compost tea (ACT)
The use of air pumps or blowers to aerate or brew compost tea. A compost of high quality is added to aerated water at the rate from 1:4. The water must have a sustained dissolved oxygen content of 6 ppm or higher to be able to support aerobic organisms and be considered an aerobic tea. Water may be warmed slightly but cooler water supports higher dissolved oxygen rates. By aerating the water the extraction and growth of beneficial bacteria, protozoa and fungi that were present in the tea is promoted. Teas are aerated from 12 to 48 hours depending what type of microbes are desired. A short brew of around 12 hours will favor the growth of fungi, while a 24 hour brew will favor the growth of bacteria and a long brew of 36–48 hours will favor the growth of protozoa. Some farmers will add small amounts of supplements that promote growth of these microbes. Molasses will promote the growth of bacteria while kelp and humic acid will promote the growth of fungi. Sometimes sphagnum peat moss or hay is added as a source of protozoa. After brewing is complete ACT should be applied to the field as soon as possible to ensure that the tea is applied to the soil when the microbes are most active. ACT is applied to the soil to boost populations of biology and increase the rate of biological activity in the soil. Sometimes ACT is sprayed on leaves as a disease preventative but the effectiveness of this application is debatable. It is important to use unchlorinated or dechlorinated water when making ACT, since chlorine will kill beneficial microbes."