Use a large plastic bin with a lid for your worm compost. The bin should have at least a 10-gallon capacity. Drill 10 to 12 holes in the bottom of the bin for drainage. The holes should be about ¼ inch in diameter. Drill ¼-inch air holes all over the lid of the bin, leaving 4 inches of space between each hole.
Line the bottom of the bin with nylon mesh. Water needs to be able to drain out of the bin, and the mesh will keep the worms from escaping.
Make the bedding for the worms. You can use well-shredded newspaper, straw, peat moss or a combination of these. Horse manure is also good bedding for a worm compost bin, but make sure the manure is well-aged. Fresh manure gets very hot as it decomposes and can burn the worms.
Age the horse manure by letting it sit outside for a few months. Turn the pile once a month with a pitchfork. You can speed up the aging process by mixing the manure with straw and shredded newspaper. When the straw is black and dried out, the manure should be aged enough to use in a worm bin.
Moisten the bedding well. It should be very wet, but not dripping. If you're keeping your worm composting bin indoors, put a tray underneath it to catch excess water because you will have to water the bin regularly.
Add the worms to the bin. Make sure you have the right kind of worms for composting. They should be small, red, and wriggly. The best species for worm composting are Eisenia foetida and Eisenia hortensis. These worms have many common names, including red wrigglers, brandling worms, tiger worms, or manure worms, and they are available at many garden stores and bait shops. Avoid using worms you find in your garden because these usually feed on soil very deeply in cooler temperatures and will die in a worm bin.
Place the bin in a warm, dark place. The ideal temperature for compost worms is around 65 degrees F. They can tolerate cooler and warmer temperatures, but they feed and reproduce most effectively in moderate warmth.
Feed the worms with scraps from your kitchen. You can also feed them small amounts of fresh horse manure. Put the food on the surface of the bin and cover it the bin. Use ¼ to ½ pound of food for every pound of worms. In the beginning, use less food because the worms will eat less as they get used to their new home. In general, do not add any fresh food or manure until the last feed you added is gone or almost gone. If you chop the food or mash it up in the blender, it will be easier for the worms to break it down.
Feed the worms vegetable cuttings, bread, pasta, coffee and cereal from your kitchen. Do not feed them meat or dairy products or very oily foods because these can rot and smell bad. Worms also do not like citrus fruits, garlic, or very spicy foods. Onion skins are okay, but the worms will take a long time to break them down.
Check the bedding every few days to make sure it is damp. It should be wet enough to leave moisture on your fingers when you touch it.