I stole this from this website,
http://www.wormkaster.com/worm_kaster_3-19-10_003.htm. I like it because it tells you the ratio to make either a small or large batch of worm tea. Hope people find it helpful!
There are many different ways to make worm casting tea, but most recipes can be summarized by saying, if you steep worm castings in water, you get "Worm Casting Tea."
If you type "worm casting tea" in your seach engine, you will be amazed at how many different recipies you will find on how to make this special brew. The most popular recipe we found is: 1 cup of castings to 1 gallon (5 cups of castings to 5 gallons) of rain water or non chlorinated tap water, 1 tablespoon of molasses and 1 tablespoon of vegetable oil (1/3rd cup of each to 5 gallons). Add aeration to this mixture and let brew for 12-24 hours.
Lets break it down:
Castings. Knowing that castings will not burn your plants in any way, you can put any amout of castings in the water that you would like. We have seen directions for as much as a shovelful of castings to 5 gallons of water, to as little as 1 cup of castings to 5 gallons of water. The more the castings, the stronger the tea. Remember, it will not burn your plants at any strength.
Rain water is the best water to use. However, chlorinated city water will work fine as long as you let the water sit for 24 hours until the chlorine dissipates. (City tap water usually contains enough chlorine to kill off the beneficial bacteria found in castings.)
Molasses. (optional) This amount of molasses is found fairly consistently on the web. Molasses is used to feed the microorganisms and the beneficial bacteria found in the castings. One article says molasses will actually double the amount of microorganisms and beifical bacteria in the castings in as little as 20 minutes.
Vegetable Oil. (optional) This amount of vegetable oil is also found fairly consistently on the web. The only time you need to add vegetable oil is if you need to spray it onto the foliage of the plant. Vegetable oil acts as a sticky agent and also can smother insect eggs and larva.
Aeration. (optional) An aquarium pump will work just fine with or without an air stone and a hose long enough to reach the bottom of your tea container. The reason for the air pump is to add more oxygen to the water, which will help the microorganisms to multiply. (A pump will provide the best results; however, the mixture can also be stirred occasionally.)
The casting tea is ready to use when it is the color of ice tea. The tea bags can be reused 2-3 times or until the tea looks too weak. Then simply empty the used casings and refill the tea bag with more castings and start over.