Quick answers: garbage disposal do's & don'ts
What are the worst things to put down a garbage disposal?
The seven worst things to put down your garbage disposal are bones, eggshells, fruit pits, fats and grease, stringy foods and peels, coffee grounds, and harsh cleaning chemicals. Each one either jams the grinding ring, hardens inside your pipes, or builds up into a clog that backs up your sink.
Can you put coffee grounds down a garbage disposal?
No. Coffee grounds clump into a dense, wet paste that coats your drain line and builds into stubborn clogs over time, even though they seem harmless. Toss them in the trash or your compost instead.
Is it OK to put grease down the disposal if I run hot water?
No. Hot water only moves grease a little farther down the line before it cools, hardens, and sticks to your pipe walls. Let fats and grease cool in a can or jar and throw them away.
What should I do if my garbage disposal is already clogged or jammed?
Turn the unit off first, then try freeing it with the hex key in the bottom slot before reaching for any chemicals. If the clog won't budge or your sink is backing up, the team at Mattioni handles disposal and drain repairs across Chester County and the rest of Greater Philadelphia.
Last Revised: 5/29/26
If you spend much time in your kitchen, you already know how much your garbage disposal does for you. It quietly handles the scraps, keeps your sink clear, and asks for almost no attention. But that easy operation can turn complicated fast when the wrong things go down the drain.
The good news is that most disposal damage is completely avoidable once you know what to keep out. We’ve been serving homeowners across Chester County and Greater Philadelphia since 1948, and our plumbers have found the same seven food materials to cause issues time and time again.
Here are those seven culprits, why they cause trouble, and what to do instead.
What Are the Worst Things to Put Down Your Garbage Disposal?
The seven items below are the ones most likely to jam your disposal, dull its grinding ring, or quietly build up inside your pipes until you’re facing a clog or backup. None of them belong in your garbage disposal.
1. Bones
The grinding plate in your disposal isn’t built to break down something as hard as bone. Instead of getting pulverized, bones rattle around against the grinding ring and wear it out. And if a fragment does slip past, it won’t make it through the drain line, which is exactly how expensive clogs get started. Bones belong in the trash, every time.
2. Eggshells
This one surprises people, because plenty of folks swear eggshells “sharpen” the impeller. The real problem is the thin membrane lining inside the shell. That filmy layer wraps around the shredder and clings to the disposal walls, and the gritty shell bits can settle in your pipes like sand. Avoid the problem altogether by composting or throwing out eggshells.
3. Fruit Pits
From a tiny cherry pit to a hard avocado or peach pit, fruit pits are simply too dense for your disposal to handle. Here’s an easy rule of thumb: if you can’t slice through it with your sharpest kitchen knife, your disposal can’t grind it either. All it does is spin against the pit and strain the motor.
4. Fats and Grease
Your kitchen drain should be a grease-free zone, just like your shower or bathroom sink. Fats and oils may pour in as a liquid, but they cool quickly and cling to your pipe walls. They harden and trap everything else that comes along. Running hot water will only push the grease farther down. Instead, let grease cool in an old can or jar and toss it in the trash.
5. Stringy Foods and Peels
Stringy, fibrous foods tangle around the grinding components, and starchy peels turn into a thick paste that cakes onto the inside of the unit. Even when that paste slips past the disposal, it keeps building inside your pipes until it eventually starts backing up. Here are some of the worst stringy and starchy foods to toss in the trash instead of the garbage disposal:
- Celery, asparagus, artichokes
- Corn husks, potato peels, onion skins
- Pasta, oatmeal, rice
6. Coffee Grounds
You may have heard coffee grounds freshen up a disposal, but they do far more harm than good. Think about how grounds clump together when you knock them out of the filter. Picture that same dense paste packing into your drain line. Over time, it’s a recipe for a serious clog. For a safe way to keep things smelling fresh, run a few ice cubes with a splash of vinegar, and a small strip of citrus rind instead.
7. Cleaning Chemicals
Everyday dish soap is obviously fine, but harsh drain cleaners and industrial-grade chemicals (contrary to advertisements) are not. “Drain buster” products can corrode the disposal and your pipes. Plus they rarely fix any underlying clog anyway.
What to Do If Something’s Already Gone Down the Drain
If you catch it early, turn the disposal off and never reach in with your hand. You can try freeing a jam with a hex wrench that fits the slot on the bottom of the unit (under the sink). A plunger may also be able to shift a clog. But if your sink is draining slowly, gurgling, or backing up, that’s a sign the problem has moved into your pipes. This is when to call in a pro for clog removal or professional drain clearing – before a small backup becomes a flooded cabinet.
Keep Your Kitchen Running as it Should
Your garbage disposal should make life easier, not leave you struggling with your sink right after dinner. Protecting it is as simple as being mindful of what you are (and aren’t) putting down the kitchen sink. And the moment something jams, backs up, or just isn’t draining right, give us a call at (610) 400-8510. You’ll get it fixed fast by a licensed plumber – so a minor annoyance never turns into a major repair.
For 75+ years, homeowners across Chester County and Greater Philadelphia have trusted our 5-star team to keep their plumbing running smoothly. So you can get back to enjoying your kitchen instead of worrying about it.
Schedule your appointment with Mattioni today or call (610) 400-8510, and we’ll take it from here.
