Separating / Harvesting Worm Cocoons (other than hand-picking)
Howdy, I've been vermicomposting at home for years, and doing it as a small business for about a year now. I've recently begun harvesting worms/castings with a rotary screen harvester I built (huge improvement to other methods).
Now I'm wondering how people separate cocoons from castings on a commercial scale? For the home bin, you can simply pick them out of the finished castings. At a larger scale, that's clearly not practical. I find that a 1/8th inch screen screen catches something around 50% of cocoons, but many fall through.
Is the solution just a more precise screen size (3/32nds of an inch)? I'm not finding much online -- wondering if this is somewhat of a trade secret for folks, or just not much discussed because it's not something the home worm keeper needs to do.
(And, yes, I could just wait for the eggs in the harvested castings to hatch, and then harvest them -- but I'm wondering how places that sell worm cocoons do it.)