How to Clean Your Garbage Disposal

To keep gunk and odors to a minimum, make sure you’re always using the disposal with water—before, during, and after grinding food.

“Oftentimes, odors from the sink actually come from foods that haven’t fully exited the disposal or drainpipes,” says Wiegand. “You can’t see it, but you can probably smell it.”

Run cold water before you turn on the disposal, while grinding food, and then for about 7 seconds after you hear the grinding stop. These three stages of water flow allow food to thoroughly move through the pipes after it leaves the disposal.

In our tests, we found that one last flush of water, once the disposal is off, is also a good idea.

In the lab, we installed each disposal in a custom rig attached to clear pipes so that our engineers could watch for clogs. They noticed that during grinding, even tiny ground-up food particles stayed suspended in water flowing through the P-trap, the squiggly part of the drainpipe that prevents sewer gases from creeping back into the house.

“The particles settled to the bottom of the trap once we turned the water off,” says Larry Ciufo, garbage disposal project leader at CR. “Turning the water back on would flush the remaining particles away.”