Washing Machine Smells Sour After Washes: Deep Clean the Drum, Gasket, and Dispenser

If your washer leaves clothes smelling sour, the problem is usually buildup and trapped moisture. Use this step-by-step deep clean for the drum, gasket, and dispenser—plus prevention tips.

TL;DR

• Sour washer smell often from detergent/softener residue + preserved moisture → biofilm (in gasket folds and dispenser especially).
• Deep-clean in this order: tub/drum-clean cycle, then scrub gasket (front-load) or rim (top-load), then wash dispenser drawer and housing, then rinse and dry everything out.
• Don’t mix bleach with other cleaners (including vinegar). Ventilate room and use your washer’s Use & Care Guide to see approved cleaners and cycles. (cdc.gov)

Why your washing machine smells sour (even after it “cleans”)

A “sour,” “musty,” or “mildew” smell after washing is almost always a washer hygiene problem—not your detergent “going bad.” Modern washers (especially HE front-loaders) use less water, so it’s easy for residue and moisture to linger. That residue makes a nice home for odor-causing buildup (sometimes referred to as biofilm) in places you can’t easily see—gasket folds, dispenser channels, and the area around the pump.

Considerations before you deep clean: quick checks + safety

• Start by emptying the washer (no clothes/towels).
• See if there’s standing water in the drum: you might have a drain issue. Run a Drain/Spin cycle first, and check to see if there’s a pump filter (most front-loaders have one).
• Gather up the supplies you’ll be using: Microfiber cloths, an old toothbrush, some dish soap, a small bowl or bucket, and either a washing machine cleaner tablet/powder, or other approved manufacturer tub cleaner.
• If you’re particularly sensitive to smells, consider starting with something like a washer-cleaning tablet, or an organic-type tub cleaner powered by oxygen bleach rather than an experiment with a “viral” mix. (Some brands recommend tub cleaners and warn against straight bleach.) (lg.com)

Step-by-step deep clean (drum, gasket, and dispenser)

Because you want to work “inside-out”, clean the innermost thing (the drum; so you’re flushing the system), then the gasket/rim, dispenser, and finally rinse and a full dry-out (dryer cycle if your washer has one).

1) Deep clean the drum / tub

1. Select your washer’s dedicated cleaning cycle (often called Clean Washer or Tub Clean). If you don’t have one, use the hottest cycle available and the highest water level that your machine can use (consult use & care guide for cycle tips). (producthelp.whirlpool.com)
2. Add scoring powder following label instructions (place in the tub; tablets in the drum, some powders directly into the main wash compartment). (lg.com)
3. Run the cycle to completion—don’t stop it mid-way. “If odor-causing bacteria are evident, run multiple cleaning cycles in succession as needed.” (affresh.com)
4. When the cycle ends, wipe any remaining residue from the bottom of the tub with a cloth (time-release cleaners may leave harmless, easy-to-wipe residue). (affresh.com)

2) Clean the door gasket (front-load) or lid rim (top-load)

Rubber gaskets on front-loaders can harbor sour odors in their folds. You’ll want to get rid of hair, lint, sludge, and detergent residue. The trick is to leave it dry.

1. Slip on gloves, pull back the folds of the gasket, and inspect top, sides, and bottom. Remove coins, bobby pins, pet hair, and lint.
2. Wipe down the gasket using warm water + a small amount of dish soap on a microfiber cloth. Use a soft toothbrush for seams and corners.
3. If visible mildew is present, scrub, rinse your cloth often, and avoid mixing products. (Some manufacturers suggest vinegar-water for wiping the gasket; rinse with plain water after if you choose to use it. Never mix vinegar with anything else.) (geappliances.com)
4. Dry it thoroughly: finish with a clean dry cloth, and leave the door ajar for airflow.

3) Deep clean the detergent/fabric softener dispenser (drawer + housing)

If the drawer smells sour, that odor can transfer right back into the wash water. You’ll be cleaning two parts: the removable drawer and the cavity where it slides in.

1. Pull out the dispenser drawer (most models have a release tab). If unsure, refer to your Use & Care Guide.
2. Soak the drawer in warm, soapy water for 10–20 minutes. Scrub the corners, siphon caps, and underside with a toothbrush.
3. Rinse well and shake out water. Dry it as much as you can before reinstalling.
4. Wipe inside the dispenser housing with a damp cloth (warm water helps). Aim for the ceiling of the cavity—residue likes to hide there. (geappliances.com)

4) (Optional but a powerful step) Clean your pump filter / coin trap

Many front-load washers have a small drain pump filter access panel near the bottom front. If the filter gets clogged with lint/hair/gunk, it can be the culprit of persistent sour, “sock” or garbage smells. Not all models have a filter that’s user-accessible—check your manual before opening anything.

1. Unplug the washer if your manual recommends it.
2. Lay towels and a shallow pan under the access area—some water will spill out.
3. Open the access door/panel, drain out any hose if present, and pull out the filter.
4. Clean debris and rinse the filter; wipe the cavity with a cloth before replacing.
5. Insert the filter snugly (or it may leak), then run a short rinse/spin to check seal. Leave the door and dispenser open to fully dry. (lg.com)

How to keep the sour smell from coming back (simple routine)

• After every load: remove clothes promptly; wipe obvious water from the gasket; leave door and dispenser cracked open to dry. (lg.com)
• Weekly (or if you notice residue): rinse and wipe the dispenser drawer area.
• Monthly: run the washer’s cleaning cycle (many brands recommend once a month / every ~30–40 loads). (geappliances.com)
• Use the right amount of HE detergent and limit fabric softener—overdosing causes residue. Some brands caution against some “natural” detergents. (lg.com)
• Occasionally: wash a load on hot (if fabric permits) to reduce residue buildup—especially if you mostly wash cold.

Methods compared: what works, what to avoid

If the washer smells sour still, what to check next?

• If the laundry room smells like sewer gas during use, check the household drain (P-trap/standpipe)—possible plumber call needed.
• Bad “sour” persists because water isn’t draining; check washer pump filter if possible. Slow draining may require service.
• There can be “outer” tub residue between inner and outer drums, sometimes requiring several tub clean cycles—or service call if odor persists.
• Laundry habits: Leaving wet clothes in the washer (even briefly) seeds the sour smell back.
• Too much product: If you see suds in the rinse, cut detergent by 25–50% and skip softener for a few cycles.

How to verify you actually fixed the problem

1. When empty and dry, open the washer and smell near the gasket and dispenser—these are “hot spots.”
2. Run a normal load with neutral-smelling detergent and no softener. If clothes smell clean, your deep clean worked.
3. If you still see water in the gasket folds/dispenser after, prioritize drying/ventilation between loads. (lg.com)

Frequently Asked Questions

References

1. CDC — Cleaning and Disinfecting with Bleach (Never mix bleach with other cleaners)
2. Poison Control — Chlorine gas: Get the facts (mixing bleach with acids/ammonia)
3. Washington State Department of Health — Dangers of Mixing Bleach with Cleaners
4. GE Appliances — How to Clean Appliances (washer gasket and dispenser info; self clean how often)
5. LG Support — How to Clean the Tub of Your LG Washing Machine (Tub Clean guidance; get a dry out of the door/drawer)
6. Whirlpool Product Help — Cleaning Washers with affresh (also Clean Washer how to)
7. affresh — How to Clean Your Washing Machine
8. Washington Post — Cleaning with vinegar dos and don’ts (cautions about rubber/materials; don’t mix with bleach)
9. LG Support — [Top Load] How to Clean the Tub (caution about undiluted bleach; prevention tips)