I define vermicompost as a mix of worm castings (vermi) and other decaying organic material (compost). I think VC is ready to use when it has 10-20% worm castings content. How can you tell? You can't really. You have to guess.

For example, if you start with 5 gal. of coir bedding and let 1 lb. of EF live in it for a month under good conditions (with appropriate feedings, temps, etc.), I'd guess that 1/4" screened VC from that bin would be great for plants. Give the worms another month to work on it and it will be even better.

The only reason I'd let harvested VC sit a month would be to allow cocoons to hatch. I have not heard of "unfinished" compost being harmful to plants. I get sprouts in my compost and worm bins all the time; plenty of unprocessed material in those.

Andrew

Thanks Andrew. About the idea of "unfinished" compost being harmful to plants, isn't that the same reason we shouldn't use leachate? You gave me an idea when you mention sprouts in compost! Perhaps I can throw in a few red beans into my harvested vermicompost, if they all manage to sprout, that will be indication that the vermicompost is good to use! :-D

This is exactly my question -- since the coconut coir looks so much like VC, telling one from the other seems impossible.

Does coir mash together like VC? Could I maybe perform a "pinch test" to see where I stood?

As long as your not mixing stuff up when harvesting (if harvesting only a portion of the bin), I'd think it should be obvious or pretty well composted if it's not actually VC.

The usual suspect are those pieces of wadded up bedding that got missed. Easy to toss those back into the bin. Veggie garbage long gone to mush and eaten. Leaves, coir etc. if it's been in there for months, it's done either way :).

I have a flow through Worm Inn, and the stuff that comes out is pretty broken up and crumbly except for the odd piece of wadded bedding or big fruit stone. If it's not small and crumbley (and not a stone etc.) it gets tossed back in on top.