10 Things You Should Never Put Down Your Garbage Disposal
A garbage disposal is one of the most convenient tools in the modern kitchen, making cleanup after a home-cooked meal significantly faster. However, many people treat this appliance like a bottomless trash can, which is a recipe for expensive plumbing disasters. While it is designed to handle light food residue, certain items can dull the blades, clog the pipes, or burn out the motor entirely.
If you want to avoid a flooded cabinet and the high cost of a professional repair, you need to be selective about what goes down the drain. To keep your kitchen running smoothly, here are the top 10 things you should never put down your garbage disposal.
1. Coffee Grounds
This is perhaps the most common mistake homeowners make. While coffee grounds are small and seem harmless, they do not wash away easily. When mixed with water, they turn into a thick, sediment-like paste that settles in the U-bend of your pipes. Over time, this creates a dense clog that is nearly impossible to clear without a plumber's snake.
2. Pasta, Rice, and Bread
Think about what happens to a pot of pasta or rice when it sits in water—it expands and becomes sticky. The same thing happens inside your disposal and drainpipes. Even after these items are ground up, they continue to absorb water and swell, creating a gelatinous mass that traps other food particles and eventually blocks the flow of water entirely.
3. Animal Bones
While some heavy-duty industrial models claim to handle small bones, most residential units are not built for this. Large bones from beef, pork, or even chicken will simply spin around the chamber, damaging the impeller blades and potentially cracking the plastic housing. If it’s too hard for you to chew, it’s too hard for your disposal.
4. Cooking Grease, Oil, and Fats
Never pour liquid grease or fatty scraps down the drain. While grease may be liquid when it’s hot, it solidifies as soon as it hits the cool metal of your pipes. This creates a "grease trap" that catches every other piece of food you send down the drain. Instead, pour grease into an old jar or can and dispose of it in the trash once it hardens.
5. Fibrous and Stringy Vegetables
Vegetables like celery, corn husks, asparagus, and artichokes have long, tough fibers. These strings can act like a net, wrapping themselves around the disposal’s motor and tangling the moving parts. This can cause the unit to jam or cause the motor to overheat and burn out.
6. Eggshells
There is an old myth that eggshells sharpen the blades of a disposal. This is false. Disposals don't actually have "blades" like a blender; they have blunt impellers. The thin, papery membrane on the inside of an eggshell can wrap around the shredder ring, while the shells themselves get ground into a sand-like grit that contributes to pipe blockages.
7. Fruit Pits and Seeds
If you’ve ever tried to cut a peach pit with a knife, you know how hard they are. Dropping a peach, plum, or cherry pit into the disposal is essentially like dropping a rock into a blender. It will cause a loud, clanging noise and will almost certainly jam the flywheel or break the grinding components.
8. Potato Peels
Potato peels are a double threat. They are thin enough to slip past the grinding lugs without being fully processed, and they are high in starch. This combination creates a thick, glue-like paste that sticks to the walls of your drainpipes and causes stubborn backups.
9. Onion Skins
While the heart of an onion is usually fine, the thin, outer "paper" skins should be avoided. Similar to eggshell membranes, these translucent layers are so thin that they can pass through the disposal's grinding chamber and get caught in the drain, acting as a "catcher’s mitt" for other debris.
10. Non-Food Items
It might go without saying, but the garbage disposal is for food waste only. Common culprits found during repairs include:
Produce stickers: These small plastic labels don't dissolve and can stick to the internal sensors or pipes.
Paper towels and napkins: These are designed to absorb water and stay strong, which is the exact opposite of what you want in your plumbing.
Trash: Plastic wrap, twist ties, and rubber bands should always go in the bin.
How to Properly Use Your Disposal
To keep your unit in top shape, follow the "Cold Water Rule." Always turn on a strong stream of cold water before you flip the switch. Keep the water running while the food is grinding, and let it continue for at least 15 seconds after the grinding sound stops. This ensures that the waste is flushed all the way through the horizontal pipes and into the main sewer line.
By being mindful of what you feed your disposal, you can extend its lifespan for many years and keep your kitchen sink smelling fresh and flowing freely.
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