A sour or rotten disposal smell usually comes from food trapped under the rubber splash guard, stuck to the grind chamber, or sitting farther down in the drain trap.
This applies to standard under-sink garbage disposals from InSinkErator, Moen, Waste King, and similar brands.
Does this affect you?
Use this if the sink drain smells bad even after running water and turning the disposal on briefly.
Safety first
- Turn off the wall switch before cleaning near the splash guard.
- Unplug the disposal or switch off the breaker for extra protection.
- Never reach into the disposal by hand.
- Use tongs for visible debris and keep fingers away from the opening.
Clean the splash guard and grind ice
- Fold back the rubber splash guard flaps.
- Scrub the underside and top side with dish soap and an old toothbrush.
- Rinse the guard thoroughly.
- Restore power.
- Run cold water.
- Grind a handful of ice cubes.
- Follow with a few small lemon, lime, or orange peels.
Deep clean with baking soda and vinegar
- Turn the disposal off.
- Pour 1/2 cup baking soda into the drain.
- Add 1 cup white vinegar.
- Let the mixture fizz for 10 to 15 minutes.
- Flush with hot water for about a minute.
- Run the disposal briefly with cold water, keeping hands clear.
If the odor remains after the splash guard and chamber are clean, it may be in the P-trap, branch drain, or dishwasher drain connection. A sewer-like smell, slow drain, or smell that returns within a day or two is a plumber-level clue rather than a disposal cleaning problem.
Repeat the ice and citrus routine weekly to keep residue from rebuilding.
Sources
- InSinkErator – Garbage Disposal Odor Troubleshooting (2025)
- Moen – How to Clean a Smelly Garbage Disposal (2025)
- Whirlpool – Kitchen Sink Odor Causes (2024)
Disclosure: This post may contain affiliate links which means I may receive a commission for purchases made through links. I will only recommend products that I have personally used! Learn more on my Private Policy page.