Watch Sallie feed castings through the trommel. She uses the trommel to separate the castings from the worms and from the unfinished material. The castings are sifted through the 1/8 inch screen into the bins below while the worms travel through the trommel and out the other end. #wormcastings #wormfarm #vermicast #vermicompost #eiseniafetida #redwiggler #compostworms #compost #trommel #wormbin