Short answer
Turn off the power, scrub the underside of the rubber splash guard with a brush, then fill the sink halfway with warm water and 1/4 cup of baking soda and run the disposal as you pull the stopper. For a quick freshen, grind a handful of ice cubes with a few lemon or lime wedges under cold running water. Never put your hand inside the disposal.
A stinky disposal can make a whole kitchen smell off, even when the counters and floor are clean. It's one of the first things people notice when they walk into a house that's been closed up, or a rental after the last tenant left. The fix is usually simple, and it doesn't take a special product.
Use these at your own risk, and test first if you're unsure about your sink's finish. One rule matters more than the rest. Never put your hand inside a garbage disposal. InSinkErator, a disposal manufacturer, says that in plain words, and we agree.
Why it smells
InSinkErator says an odor coming from the disposal is usually a sign of food buildup. The most common cause is not running enough water while grinding and after. Food bits stick to the walls of the grinding chamber and to the underside of the rubber splash guard, and in a warm kitchen they start to smell fast.
Grease makes it worse. InSinkErator says never to pour grease or fat into a disposal or drain. It coats the inside, traps food and smells.
The deep clean
This follows the maker's own steps, with a little detail added.
- Cut the power. Turn the disposal off and unplug it under the sink, or switch off its breaker. Don't rely on the wall switch alone.
- Scrub the splash guard. That floppy rubber collar in the drain opening is where most of the smell lives. InSinkErator says to clean its underside and the upper lip of the grinding chamber with a scouring pad. We use a long-handled scrub brush with a little dish soap so our fingers stay out of the opening. Flip the flaps up with the brush and work around the whole ring.
- Restore power.
- Fill and flush. Put the stopper in and fill the sink about halfway with warm water. Stir in 1/4 cup of baking soda. Turn the disposal on and pull the stopper at the same time. The rush of water carries loose bits down and out.
If something fell in, like a bottle cap or a spoon, cut the power first and use tongs or pliers to pull it out.
The quick freshen
InSinkErator's tips suggest dropping ice cubes mixed with lemon or lime wedges into the disposal to freshen it. The ice knocks loose some buildup and the citrus leaves a clean smell. Run a medium stream of cold water, turn on the disposal, and let it grind until it sounds empty. Keep the water running a few more seconds.
It's a nice once-a-week habit, or the last thing to do before guests come over.
Everyday habits that prevent the smell
- Run cold water every time. InSinkErator says to run a moderate flow of cold water while grinding and for a few seconds after.
- Keep grease out. Wipe greasy pans with a paper towel and throw it in the trash before washing.
- Feed it a little at a time. Stuffing in a whole plate of scraps at once leaves more behind.
- Skip harsh products. InSinkErator says to avoid fats, oils, harsh cleaning products and other non-food items in the disposal.
When it isn't the disposal
Sometimes you clean the splash guard, flush it and the smell is still there. A sewer or rotten-egg smell can come from the drain line or trap instead. If the dishwasher drains through the disposal, a clogged dishwasher filter can smell too, so check your dishwasher manual for how to clean it.
If the smell keeps coming back, or water drains slowly or backs up, call a plumber. Don't pour in one product after another hoping something works.
Never mix these
Drains are where people mix chemicals by accident, because everything ends up in the same pipe.
- Bleach and ammonia make chloramine gas.
- Bleach and acids, including vinegar and some toilet bowl cleaners, make chlorine gas. Poison Control says chlorine gas burns the eyes, nose and throat and can injure the lungs.
- Hydrogen peroxide and vinegar in the same bottle form peracetic acid. The Missouri Poison Center describes it as corrosive.
If someone in the house already poured a chemical drain opener into the sink, don't add baking soda, vinegar or anything else on top of it. Read that product's label for what to do, open a window and keep everyone away from the sink until it's handled. If anyone breathes in fumes or gets splashed, get them to fresh air, rinse skin and eyes with water, and call Poison Help at 1-800-222-1222.
Storage
The American Cleaning Institute says to keep products in their original containers with the label on, and to store them out of sight and reach of children and pets. That goes for the box of baking soda under the sink too. A cabinet lock is cheap and worth it if you have small kids.
Recipe card
How to Clean and Freshen a Smelly Garbage Disposal
You need
- 1/4 cup baking soda
- Warm water, enough to fill the sink halfway
- A handful of ice cubes and 2 or 3 lemon or lime wedges
- A long-handled scrub brush, dish soap and a sink stopper
Steps
- Turn off the disposal and disconnect its power at the plug under the sink or the breaker.
- Lift the rubber splash guard with the brush and scrub its underside and the top rim of the grinding chamber with dish soap. Use the brush, never your hand.
- Turn the power back on. Put the stopper in and fill the sink halfway with warm water.
- Stir in 1/4 cup baking soda. Turn the disposal on and pull the stopper at the same time to flush it.
- To freshen, drop in a handful of ice cubes and a few citrus wedges and run the disposal with a medium stream of cold water until the grinding stops.
- Keep the cold water running a few seconds after the grinding ends.
Cautions
- Use at your own risk. Test a small hidden spot on your sink finish if you're unsure.
- Never put your hand in the disposal, even with the power off. Use tongs to fish things out.
- Never mix bleach with ammonia. It makes toxic chloramine gas.
- Never mix bleach with vinegar or other acids. It makes chlorine gas.
- Don't put hydrogen peroxide and vinegar in the same bottle. They form corrosive peracetic acid.
- If anyone already poured a drain opener down the sink, don't add anything else. Follow that product's label.
- Keep grease, oil and harsh cleaning products out of the disposal.
- Store baking soda and cleaners out of reach of kids and pets. Poison Help is 1-800-222-1222.
Test a small spot first
Try any cleaner on a hidden spot and wait before you do the whole surface. Never mix bleach with ammonia, vinegar or other cleaners. Open a window or run a fan, label homemade bottles, and keep them away from kids and pets. Keep vinegar and other acids off natural stone. Follow the product label. You use these tips at your own risk.
Common questions
Why does my garbage disposal smell?
InSinkErator, the disposal maker, says an odor is usually a sign of food buildup, often from not running enough water during and after use. Grease poured down the drain makes it worse.
Can I put lemon peels in the garbage disposal?
InSinkErator's own tips suggest grinding ice cubes mixed with lemon or lime wedges to freshen the disposal. Cut them into small wedges and run plenty of cold water.
Should I use hot or cold water with a garbage disposal?
Cold while it's grinding. InSinkErator says to run a moderate flow of cold water during use and for a few seconds after. Warm water is for the baking soda flush with the disposal's power handled safely.
What if the smell comes back right after cleaning?
Check the underside of the rubber splash guard again, since gunk hides there. If the sink still smells like sewage or rotten eggs after a good cleaning, the problem may be in the drain or trap, and that's a job for a plumber.
Rather have someone else do it?
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Sources
- There's an odor coming from my garbage disposal (InSinkErator support) (accessed Oct 8, 2026)
- FAQs, garbage disposal support and advice (InSinkErator) (accessed Oct 8, 2026)
- Chlorine gas, what happens if you mix bleach and other cleaners (Poison Control, National Capital Poison Center) (accessed Oct 8, 2026)
- Some Things Just Don't Mix (Missouri Poison Center, updated Jul 7, 2025) (accessed Oct 8, 2026)
- Cleaning Product Safety (American Cleaning Institute) (accessed Oct 8, 2026)