Here is a question from Andre:
After 5 months on vermicomposting I decided to harvest some
booty. I made a bucket/screen getup with 1/4 holes. After running
about 1/4 of the castings through it I ended up with about a cup full
of spongy amorphous castings like the consistency of drying mud. The
compost is coming out of 20gal plastic bins that are drilled full of
1/8 inch holes. Any advice on how to get it dry and free of the tiny
Great question, Andre – and likely a very similar situation as that faced by countless other enclosed-plastic-bin vermicomposters!
I hate to say it, but unfortunately there is no getting around the fact that it’s more difficult to produce really nice worm compost in an enclosed plastic bin system – even with LOTS of air holes drilled in the sides and lids (even with fancy vents). Plastic is simply TOO effective when it comes to retaining moisture!
The good news is that you have a number of options as far as remedying this situation goes. For starters, you might think about switching over to a completely (or at least partially) lidless approach. It is amazing how much of a difference the simple act of removing your bin lid can make in terms of reducing the moisture in the bin, speeding up the vermicomposting process, and even helping to create a much nicer end product!
If you don’t want to leave your lid off all the time, you might try simply doing so on days (and during daylight hours) when you happen to be around – this alone could have a pretty significant impact on the system. Whatever your approach (lidless or semi-lidless) I DO recommend that you always maintain a nice thick layer of bedding in the bin (as much as the bin will hold). This way you will help to keep light from bothering the worms (and influencing their level of activity in the bin), you help to prevent the bin from drying out too quickly, and you help to keep your system “off the radar” of various annoying critters (like gnats and fruit flies).
Assuming you have no interest in using a lidless bin…
Your other option involves some sort of vermicompost remediation before attempting to screen and/or use the material.
This does not need to be a complicated process at all! Simply dumping the contents of your bin out onto some sheets of corrugated cardboard (or a larger bin with layers of cardboard at the bottom), then letting everything sit for awhile should work wonders.
Don’t forget to regularly break-up and mix the materials (a small hand fork should work well) during the drying process though! I kid you not, when I say that there must be potential real world building applications for the use of vermicompost “cement”! This is incredibly hard stuff if left alone to dry.
The drying stage has a number of great benefits, apart from improving the potential for screening and using the material. For one thing, it provides the compost with the time to fully stabilize in a nice, aerobic environment – very important for the creation of high quality vermicompost. Anyone who has dumped out the contents of a mature plastic worm bin will undoubtedly agree that the aroma that wafts up 9 times out of 10 is anything but aerobic!
This drying period can also provide you with the opportunity to extract the zillions of baby worms (including those still in cocoons) usually remaining in the material! One approach that can work involves adding some watermelon, cantaloupe, or really any moist fruit waste to the top (ideally covered up with bedding materials) then waiting for the little wigglers to start congregating underneath and scooping them up when they do. Given enough time, even the the most recently deposited cocoons should release their weeny, wiggling cargo.
Anyway, I hope this helps, Andre!