Below are instructions and notes on what I have learned so far about making a worm bin to compost food waste. So far, it seems to be working, but I'm absolutely no expert, so please don't take anything as gospel!

Materials:

• Three totes: they should be 18- to 24-gallon sized and opaque -- worms don't like light. If you live by yourself, you might be fine with a 10-gallon one; the surface area determines how much the worms will eat. It will make your life easier if the top snaps firmly on! So far, my experiments have shown that the $3 Sterlite totes are too cheap and the $12 hardcore Rubbermaid ones seem pretty secure. There is an intermediate set, the $7-$9 Rubbermaid "storage totes" that only snap at the handles but have better edges than the $3 totes, but I haven't yet tried them myself.
• Eight empty soda cans or plant pots or something (to keep the totes from nesting so tightly that no air gets in the air holes)
• Some newspaper (for bedding)
• A bunch of red wigglers (eiseina fetida, if you're feeling fancy). You can get these at bait shops; I've been starting bins with about 150 worms (which runs about $15 in the Boston area), and it seems fine but they don't go through food super-fast, so you could probably also use more.

  Instructions

  If you have a drill, making the bin is easy and takes 10 minutes!

  • Take two of the totes, and your trusty drill. Drill a mess of 1/4-inch holes, spaced about 2 inches apart, in the bottoms of the two bins. Drill a row of 1/16-inch holes around the sides of each of the bins near the top.
  • Take one top, and drill a bunch of 1/16-inch holes in it too. (Watch out. These processes break tiny drill bits. Please wear eye protection!)
  • Stick four soda cans in the corners of the third, untouched bin. Stick one of the drilled bins on top of the soda cans.
  • Stick four more soda cans in the corner of the top bin. These will eventually support the third bin.
  • Tear up a bunch of newspaper. Put about half of it in the bin. Take the other half, wet it, and then squeeze the extra water out. Add that to the dry paper in the bin and mix; it should feel like a damp sponge to the touch. You want to end up with the bedding about four inches deep.
  • Bury some food scraps in one corner, if you have them.
  • Add worms! (If your worms didn't come with dirt, throw in a handful of dirt or sand as grit, too.)
  • Bob's your uncle! You have a worm bin!

  Care and feeding

  • Bury some food in the bedding once a week or so to start. As they reproduce, they'll be able to handle more: eventually, a bin should be able to process one pound of food scraps per week for every square foot of surface area. They'll eat the bedding too, so don't worry hugely about starving them. Bury it in different places each time. (If you're organized, you can bury it in six or eight locations in rotation, and then you'll be able to gauge how much they're making it through.)
  • If you don't get any liquid dripping into the bottom tote, feed them more wet foods or sprinkle water into the bin. When you do get liquid, it's also great compost and can go straight on to your plants.
  • If your worms are trying to escape or are hanging out on the walls of the bin when you look in, its probably too wet for them. Try adding a layer of dry paper on top of the bedding
  • Don't give them meat, more than little bits of dairy or eggs, or too much oily or spicy food. Do give them fruit and veggie scraps, egg shells, coffee grounds, paper filters, bread crusts, etc. They can also eat office paper and black and white junk mail; watch out for colored inks, which can contain lead.
  • They tolerate a wide range of temperatures, but prefer 55-70. They're potentially at risk if the bedding gets to down to freezing or up over 80 degrees or so.
  • When the stuff in the bottom bin is mostly crumbly brown stuff and you can't easily bury more food, take off the lid and stick bin #3 on top of the soda cans you cleverly put there when you started. Put fresh bedding in Bin 3 and start feeding only in that bin. The worms will allegedly migrate up over the course of about a month, leaving you free to remove the middle bin and use its composty contents!