We’ve had a worm bin for a couple of years now. It’s not fancy – just a couple of cheap plastic tubs stacked one inside the other – but it works well. The worms process food waste very quickly so there are no bad smells and no fruit flies. And you get great garden amendments as outputs: vermicompost and worm tea.
My only complaint about our current system is that it’s a pain to harvest the finished compost. There are various ways of separating castings from live worms and undigested food, but they all seem messy and tedious to me. So when I came across a design for a continuous flow worm bin I was intrigued. The key idea is to use a column of material rather than a heap. You simply keep layering food and bedding material on top while harvesting finished compost from the bottom of the stack.
Do a web search for ‘flow through’ or ‘continuous flow’ worm bin and you’ll see many different designs. I chose one that is a little more aesthetically pleasing and adapted it a bit. I rather like how it turned out. Now I just hope it works as advertised. It’ll probably take 6 weeks before I can start harvesting.