I have been raising African nightcrawlers for four years and have just recently started to sell the castings. A reporter did a story on castings and included another person who claims to have 100%wormcastings in two weeks with a system he bought from Australia. He saw my castings and said his are pure and mine are at the most 40%. He claims his system feeds worms a certain amount based on the bin size and number of worms. MIne are in the beds 6 to 12 months though I do change partial bedding throughout the time.Any way possible this guy could have such a system and how do I determine the % of my castings? Thanks!

Rachel,

That is a good question. casting purity is going to depend on harvest method. Meaning how you remove the castings from the worms and bedding.

If you just remove the worms and use the bedding and all as a soil amendment that would be vc (vermicompost) which will have castings, compost, nematodes, and all but is not 100% castings.

When I harvest I remove the worms, then the eggs and vc, and what I have left is just castings. Now I know that there is still some vc in the mix, but it is mostly castings. In the pile of castings, I only use the best looking, premium castings to sell as just castings. The rest of it is mixed with the vc and sold as potting soil.

I could keep going but it would end up as book. Hope this helps.

How do you remove the vc from the castings? Just smaller screening? Thanks very much for your time!

Yes, 1/8" screen, then rescreen through overlapped 1/8"...

Without getting bogged down in the how and why most prospectors use screens to classify dirt before panning . Any prospecting supply store can sell you screened pans that are convenient to use . They are like gold panning pans but the bottom is screen and the sides are straight . . The final one I use for castings is 1/16th inch squares .I do plan to make a screen tumbler like you would see when tickets are tumbled for a drawing . I think if I take some 1X12 boards and cut circles I will have 3 round pieces (1 X 11 or so). I will cut the inside out of one of them . I will use the solid round pieces for ends and the "circle" for support in the middle . Put screening around and make a door , drill a hole at each end for , let's say a length of rebar . I can then make a support for each end .(nothing fancy) . Put it over a tub and turn it while hanging out OR hook up a small motor with a belt to a pulley . A small variable speed drill comes to mind . Some ball bearings will bust up clumps of casting . Not sure of the size of the ball bearings yet .An old windshield wiper motor hooked up to a 12V battery will do nicely also . If you can find an old headlight switch that also dims the dash lights you can hook it up inline to control speed .
If you use plywood you can make bigger circles thereby increasing your potential amount to be processed .

I also spoke with this guy Rachel spoke with and he didnt seem to understand much about worms at all couldnt even tell me latin name for his worms.... and I think his 1000 % catings dont come from his worms.............