A quick rundown on 3 ways to separate those worms from the worm castings.
Light Harvest: Remove top bedding to get to lower “working” layer of worms/worm habitat
1. Dump bin contents, or as much as you want to harvest, onto a tarp, bin lid, shallow pan
2. Place in strong sunlight or under a strong light
3. Worms will “dive” deeper to avoid light
4. About every 5 minutes, scrape worm habitat off along the top and sides until you are to the bottom–where all the red wigglers are!
5. Place worms back in their bin with combination of fresh half decomposed organic compost, any large stuff from worm habitat that needs more processing, old bedding, and more bedding if needed.
Cardboard Box method–this is for those really wet bins that are almost solid “muck” and hard to separate
I place the “worm habitat mix” in a shallow cardboard box with a small rind of melon or pumpkin up top and cover with a damp newspaper and shut the box (I just do a simple over/under with the lids). I then forget about it for 2-3 weeks. Voila! I open box, see more red wigglers than you would ever imagine (around the rind of food), take the worms out and place back in a working worm bin, and check the readiness of the VC for use. Most of the time it is drier and about right at this point. If needed, I shut it back and let it “process” for another week or more–and usually find yet a few more worms! At this stage, my hope is that any cocoons have hatched, and any worms are too immature to have “laid” any more.
Compost Sifter Method
Using a compost sifter with a 1/8 in. screen, that can fit over a “tote”, place a few handfuls of worm habitat in the sifter.
Check mix for worms. Place those back into worm bin.
Shake sifter to separate castings to bin below. Check sifter for more worms.
Throw unprocessed stuff in sifter back into worm bin.