People vermicompost at home for different reasons, some just want to get rid of kitchen scraps as quickly and sustainable as they can. Some have no space for an outdoor compost or want to continue composting through the cold winter months. Others are in it for the castings.
Technically any casting that emerges out of the back end of a worm will be perfectly balanced organic fertilizer. A tiny “drop” of brand new soil. Complete with all the macro and micro nutrients growing plants need. It can be beautiful fluffy black gold, it can also be a sloppy, mushy glob of wet “mud” in your bin. If your goal is to produce instantly usable soil for your home and garden you’ll need to maintain your bin to fill that purpose.
Moisture content and bedding are the tools for high quality castings and there’s plenty of tricks for drying out wet bins. Raw food vrs. frozen food is a good place to start. Freezing your organic waste plays a duel role. Keep in mind that worms can’t “eat” anything until bacterial decomposition has begun. Anything you can do to increase the surface area of your worm food will help speed the composting process. Freezing actually bursts the individual cell walls and allows the bacteria instant access to begin decomposition. It also is a great way to control the moisture of your bin. Once thawed this material will shed some of it’s water. If your bin is to wet simply discard the liquid before using the solids. Raw food tends to compost much more slowly and will retain the water longer leaving your bin a dryer environment.
Bedding eventually composts too. Newspaper will disappear faster than straw or cardboard. The bedding to food ratio can change the texture of your vermicompost. Keeping an eye on moisture and bedding is the key to having instant castings, it’s an interesting balance and a personal choice. Each vermicomposter will find the system that works best for them. It depends on your needs and goals.