These machines dry, grind, and cool food waste into as little as a tenth of its original volume. Most cycles take a total of three to six hours, so you can run more than one cycle per day. The finished product can be mixed in with garden soil to provide nutrients and improve soil texture. They range in size from countertop models to stand-alone units that are about the size of a traditional compost bin. Most can process fruit and vegetable scraps, brown paper, soft bones, and small amounts of other food waste such as pasta or bread. They can’t handle fibrous materials such as pits, nuts, watermelon rinds, or pineapple leaves. You should also avoid putting bioplastics and pet waste in a compost machine.