Leachate, sometimes incorrectly referred to as worm tea, worm juice, or worm wee, is not actually a desirable byproduct of vermicomposting. In most cases the production of leachate means there is too much moisture in the bin, likely due to overfeeding, and can lead to other problems in the bin. Many worm bins on the market have spouts or collection areas for the liquid, giving the impression the liquids production is a good sign, however, you should avoid leachate. These collection methods are to assist in draining once you have overfeed.
Leachate vs Worm Tea⚓︎
Leachate is excess liquid due to over feeding.
[[Vermicompost-Worm-Tea|Worm Tea]] is a deliberately-produced liquid, where vermicompost is suspended in water that is currently aerated, or agitated, to oxygenate the water and create an explosion of microbial life.
Proper feeding and adding additional bedding like paper shreds and cardboard when adding moist foods will prevent the excess liquids from leaking and allow the worms to process the liquid.
Checking for proper Moisture Levels will help keep the bin healthy.
Issues Created by Leachate⚓︎
As excess moisture seeps down into the vermicompost, it displaces air in the pore spaces. The microbes in the vermicompost consume the available oxygen in these pore spaces that are now occupied by the leachate, eventually producing an anaerobic, oxygen-deficient environment. This is bad for both the worms, and the microorganisms which are helping to maintain a healthy bin.
Leachate is also not a byproduct of the worms themselves in most cases, but rather is the saturation of the compost, meaning the liquid has not been processed and is simply juices from the un-composted foods.
In normal conditions, Red Wigglers (Eisenia Fetida) should be near the top of the bin eating the fresher organic waste. However, worms are also attracted to water, and will often follow it to undesirable depths. In a continuous flow or multi layer bin system, worms moving to deeper depths means harvests can often be full of worms, reducing the healthy population.
Difficult Screening of Harvests⚓︎
Even without wormy harvests, wet vermicompost is difficult to screen as it will tend to clump and form aggregates that are too large. When harvesting the processed vermicompost you want to keep it with a lower humidity so it does not spoil or clump.