Is it brewing a few worms in a cup of hot water? Eww, nope! It is just the liquid form from vermicomposting. Some people have the misunderstanding that the liquid mixture retrieved from the bottom of the worm casting bin is worm tea. But, this liquid is known as leachate. Worm tea or Vermi-tea is an intricately prepared mixture of oxygenated water and worm castings. Leachate is not as nutritious and microbe filled as worm tea and is a smelly by product which contains bad microbes.