What is compost tea? As it is with many things, it is many things to many different people. What do you think compost tea is?
Not all compost tea is equal.
Way back in the "good ol' days" before electricity and the invent of chemical fertilizers and pesticides, the gardener/farmer had natural ways to coax the most they could get from the land. Back then they'd throw a heap of manure in a bucket, add water and let it sit for a spell (usually 7 to 14 days) until the water was a nice dark "tea" color. Over the years the art of composting was developed and instead of using manure, the finished compost was used to make a tea which, in both cases, was used as a liquid fertilizer. The by-product of this method would officially be called "Compost Extract".
Take a leap forward to present day. Soil health has become a science and along with that has been the development of the science of vermicomposting and the bacteria or fungal rich tea that can be produced from the finished product. But in order to do that requires more than dumping some vermicompost in a bucket and letting it sit. Likewise, the "compost leachate" that is the dark solution obtained from the bottom of a worm bin or compost pile is not even close to the same thing as high quality compost tea or AACT ( Actively Aerated Compost Tea) that the experts are referring to when they speak of Compost Tea. Compost tea, in modern terminology, is a compost extract brewed with a microbial food source — molasses, kelp, rock dust, humic-fulvic acids are common ingredients. The compost tea brewing technique is an aerobic process that extracts and grows populations of beneficial microorganisms
The experts will tell you the most valuable compost tea is one that has been brewed with an aerator and some sort of food source for bacteria. Because that is what you should be growing when you brew compost tea. The bacteria is what makes REAL COMPOST TEA a great value to the grower.
This is a relatively new field and there are many differing opinions, but there are a few facts that are hard to dispute:
Good compost is an absolute necessity - If you are going to brew a high-quality compost tea then you have to start with a high-quality compost. You can only grow whatever you have present in your compost. Therefore, if you are a professional grower, or if you are battling a particular problem you will want to know exactly what your have in your compost and you will want to have it tested. But if you are just a gardener trying to improve on the health and productivity of your families crops then if you build a healthy compost with a variety of materials that should suffice.
A food source is essential - In order for your micro-organisms to grow in sufficient numbers there must be a food source. The goal is to provide enough food to maximize your growth of beneficial organisms without over-producing and causing the tea to go anaerobic because the organisms use up all the available oxygen.
Oxygen - All living organisms need oxygen to live! The organisms in your compost tea are no different. If there isn't enough oxygen while you are brewing you will start growing anaerobic pathogens which are toxic to plants. By keeping the oxygen levels high you are growing the good biology, which is what you want for your plants.
It has been asserted that compost tea is a fertilizer. Let's be
clear that neither LCE (liquid compost extract) nor ACT (aerated compost
tea) is a fertilizer in the traditional sense. Both are biological,
microbial stimulants with some nutritional value, but NOT fertilizers.
You can add some organic fertilizers like fish hydrolysate to the teas if you are looking to do fertilization at the same time.
This is a real life application of a brewed compost tea shared with me in a newsletter from the company where I bought my compost tea brewer.
Individual Foods for your 5-gallon brewer ($1.50/bag)-These food packets come ready to use with your own compost for one 5-gallon brew.
Re-usable mesh bags ($5.50-$16.00 depending on size of brewer)
Another Variety of