“What types of kitchen food stuffs should not be put in the worm bin?” ~ Mike
Here are some basic guidelines for you.
For starters, it is definitely best to NOT add any meats, dairy or oily foods to your bin.
These can petrify, causing really foul odors and harming the worms, and may support the growth of dangerous microorganisms as well. Don’t worry too much about tiny quantities of any of these – salad with oily dressing should still be ok, as would a stir-fry cooked in oil.
Directly adding any sort of oil or grease however is not a good idea.
Oily liquids can coat the surface of the worms, impeding respiration and likely causing general irritation.
Speaking of irritation, you may want to avoid adding any spicy foods or those containing other potentially problematic compounds (such as excess salt). Hot peppers are an obvious choice in the spicy food department, and onions and citrus fruit are prime examples of other food you’ll want to add in moderation.
Red Worms are very tolerant of acidic conditions, but adding too much acidic food waste can wreak havoc on the vermicomposting ecosystem, causing your worm system to go ‘sour’. Aside from the obvious acidic foods like citrus, you may want to go easy on tomato and pineapple wastes, among others.
Starchy food can cause a bin to go sour as well if added in large quantities – they tend to become thick and goey, impeding air flow. As anaerobic conditions develop they can actually start to ferment, creating alcohols and other potentially harmful metabolites.
While not in the “kitchen food stuffs” category, some other materials you should avoid adding to a regular worm bin include cat/dog or human fecal matter. These all CAN be vermicomposted, but I’d highly recommend doing so in a completely separate (and very well ventilated) system.
These wastes can contain a lot of coliform bacteria along with various other nasty organisms. If done properly though, vermicomposting can certainly be a great way to process these wastes rather than sending them to the landfill or waste treatment plant.
Hope this helps!