This email came from Ryan P:
I have been a fan of your site for a while (recently joined e-mail list).
I have a question about harvesting the compost from my bins…. I have a feeling that it is time to harvest the compost from one of my bins – I grabbed out a couple big handfuls of material from the bin, placed it in little piles under a light and got the “little guys” (ENCs) back into their bin. The compost I got is wet and sticky — if I squeeze a handful 1-2 drops of water come out, then it is like a mud ball — is this normal? All the pictures I see online look soft and dry/crumbly.. If I let it dry out will it get crumbly, or have I done something wrong? … There is still quite a few pieces of corrugated cardboard throughout the bin (it was a big part of the bedding since I get a lot for free). Should I wait until they eat ALL the bedding materials before harvesting (or just pull it out when I harvest)?
Other than that I feel it is going very well (thanks to your site). I started with about 60 ENCs in a 12″x18″ bin, and now it is LOADED with them (and I have started a 2nd bin).
Thanks for the kind words (I wrote “wormds” on my first try! lol). The good news is that “wet and sticky” vermicompost is very common, especially in any sort of enclosed plastic system. The beautiful, dry, crumbly stuff you see online has likely been: A) produced in a well-ventilated flow-through system, and/or B) allowed to sit (in well ventilated location) and dry/cure (more on this in a minute). It has also likely been screened!
The material I’ve been removing from from my VB48 and Worm Inn Mega systems recently fits that description for exactly those reasons (in the case of the ‘Mega’ vermicompost, I let it sit for a number days in an open tray and then screened it)! But most of the vermicompost I have harvested from plastic bins in the past has had more of a wet, gooey consistency. Now, that’s not to say that gooey is necessarily bad! Not at all.
I can still remember my very first vermicompost harvest (from the second bin I ever set up). I scooped the (rather muddy) stuff straight out of the bin and deposited it straight into the pot of a tropical plant I owned at the time. The plant grew like crazy after that – and I was definitely sold on the benefits of worm castings!
One important thing to mention about letting vermicompost sit and dry. It is VERY important that you mix/break it up on a regular basis during the drying process. If allowed to dry as a big solid clump, the material will be next to useless.
As for the unprocessed materials still in the bin – what you might try doing is stop feeding the worms for a couple of weeks. This allows them time (and gives them incentive) to process a lot of the left-overs in the system (assuming you have a decent population of worms in there). Whatever is not processed can either be removed before harvesting, or screened out (you can learn about a simple homemade screener design here: Super Simple Vermicompost Screener). This stuff is excellent “living material” that can be re-introduced to your system over time to help optimize the process.
Hope this helps!