Your Dishwasher Could Be Growing Mold—Here’s How to Clean It Properly

That musty smell coming from your dishwasher may not be leftover food at all. If you notice black, pink, white, or slimy buildup around the door seal or filter, your dishwasher could be harboring mold—and simply running another wash cycle won’t necessarily solve the problem.

Dishwashers spend much of their time warm and damp, which makes them an easy place for mold and mildew to develop. The good news is that a thorough cleaning can usually get rid of the buildup and help prevent it from coming back.

How to Tell if Your Dishwasher Has Mold

Mold isn’t always obvious. Sometimes the first warning sign is simply an unpleasant smell.

Look for:

• A musty or sour odor.
• Black, gray, white, orange, or pink spots.
• Slimy buildup around the rubber door gasket.
• Food and residue trapped inside the filter.
• Dirty or clogged spray-arm openings.
• Standing water with an unpleasant smell.

The door gasket, filter, and areas around the dishwasher drain deserve particular attention because moisture and debris can collect there.

Why Mold Grows Inside a Dishwasher

A dishwasher may use hot water and detergent, but that doesn’t mean every part of the machine stays clean.

Food Residue

Small pieces of food can become trapped in the filter and around the drain. As they break down, they can contribute to unpleasant odors and microbial growth.

Constant Moisture

After a wash cycle, the inside of the dishwasher can remain warm and humid. Closing the door immediately can trap that moisture inside.

Dirty Filters

The filter catches food particles and grease. If it isn’t cleaned regularly, that buildup can become a source of odors and grime.

Detergent and Mineral Residue

Hard water and detergent can leave deposits on the interior surfaces, making it easier for grime and biological buildup to accumulate.

Before You Start Cleaning

If you’re dealing with visible mold, wear rubber gloves and avoid creating unnecessary splashes or aerosols.

Also, don’t mix cleaning products. Never combine bleach with vinegar, ammonia, or other cleaners.

If your dishwasher manufacturer provides specific cleaning instructions, follow those instructions first.

How to Clean Mold From Your Dishwasher

1. Empty the Dishwasher

Remove all dishes, glasses, utensils, and other items.

Take out the racks and utensil basket if they’re removable.

This gives you better access to the areas where grime tends to hide.

2. Clean the Filter

The filter is one of the most important parts to clean.

Remove it according to your dishwasher’s instructions and rinse it under warm running water.

Use a soft brush and a little dish soap to remove trapped food, grease, and residue.

Pay particular attention to the edges and fine mesh.

3. Scrub the Door Gasket

The rubber gasket around the door can collect moisture, food particles, and grime.

Wipe it thoroughly with warm water and mild dish soap using a soft cloth or toothbrush.

Pull the folds of the gasket back gently so you can reach hidden buildup.

For stubborn residue, repeat the cleaning rather than aggressively scrubbing the rubber.

4. Clean the Spray Arms

Check the small holes in the spray arms.

Food particles and mineral deposits can block these openings and reduce water circulation.

Remove the spray arms if your model allows it, then rinse them and gently clear blocked holes with a soft brush or another manufacturer-approved method.

Avoid using anything that could enlarge or damage the openings.

5. Wipe the Interior

Use a soft cloth with warm water and mild dish soap to wipe the dishwasher walls, door, edges, and bottom.

Pay extra attention to areas where food residue has accumulated.

If there is standing water, remove it according to your dishwasher manufacturer’s instructions and investigate the cause rather than simply ignoring it.

6. Run a Cleaning Cycle

Once you’ve manually removed the visible buildup, run an empty hot cleaning cycle.

For this step, use a dishwasher cleaner recommended by your appliance manufacturer or a dishwasher-cleaning product designed for the job.

While vinegar is often suggested as a DIY dishwasher cleaner, manufacturers may not recommend repeated use because its acidity can potentially affect rubber components and other materials.

What About Baking Soda and Vinegar?

You’ll often see advice to use vinegar followed by baking soda.

Although both are common household cleaning ingredients, combining them isn’t a particularly effective way to clean mold. They react with each other and largely neutralize one another.

For moldy areas, physically removing the buildup with detergent, a soft brush, and thorough rinsing is more important than creating a dramatic fizzing reaction.

If your dishwasher manual specifically recommends a particular cleaning method, use that instead.

Let the Dishwasher Dry Completely

After cleaning, leave the dishwasher door slightly open so air can circulate.

Dry the gasket and any areas where water remains trapped.

Reducing moisture is one of the easiest ways to make the dishwasher less welcoming to mold and musty odors.

How to Prevent Mold From Coming Back

A few simple habits can make a noticeable difference.

Leave the Door Slightly Open

After a cycle finishes, allow the interior to ventilate if your dishwasher and kitchen setup make this safe.

Clean the Filter Regularly

If you use your dishwasher frequently, inspect the filter every few weeks and clean it when necessary.

Wipe the Gasket

Give the rubber seal a quick wipe regularly, especially if you notice food particles or moisture collecting inside the folds.

Remove Large Food Scraps

You don’t need to completely wash dishes before loading them, but scrape large pieces of food into the trash or compost.

Don’t Ignore Standing Water

A small amount of water can be normal in some dishwasher designs, but unusual or persistent standing water may indicate a drainage problem.

If water remains after repeated cycles, check the manufacturer’s troubleshooting instructions or contact a professional.

Common Mistakes to Avoid

Don’t make these cleaning mistakes:

• Don’t mix bleach with vinegar or other cleaning products.
• Don’t use abrasive scrubbers that can damage the dishwasher’s interior.
• Don’t forget the filter.
• Don’t ignore a dirty door gasket.
• Don’t repeatedly use acidic cleaners unless your manufacturer says they’re safe.
• Don’t close a wet dishwasher immediately after every cycle if your manufacturer recommends ventilation.
• Don’t continue using the appliance normally if you suspect a serious drainage or mechanical problem.

How Often Should You Clean Your Dishwasher?

A simple maintenance schedule can help:

• Every week: Check and wipe the door gasket.
• Every few weeks: Inspect and clean the filter as needed.
• Monthly: Run a dishwasher-cleaning cycle if recommended by the manufacturer.
• Every few months: Give the entire interior, racks, spray arms, filter, and seals a more thorough inspection.

If your dishwasher is used heavily, you may need to clean it more frequently.

When Should You Get Professional Help?

Cleaning can solve many cases of surface mold and odor, but persistent problems shouldn’t be ignored.

Consider getting professional help if:

• The dishwasher repeatedly develops a strong sewage-like odor.
• Standing water keeps returning.
• The dishwasher isn’t draining properly.
• Mold appears to be coming from inaccessible internal components.
• There is a leak around the appliance.
• Cleaning doesn’t resolve the problem.

Final Thoughts

A dishwasher can clean your dishes every day and still need cleaning itself.

If you notice a musty smell or mold-like buildup, start with the areas most likely to collect moisture and debris: the filter, door gasket, drain area, spray arms, and interior surfaces.

Clean the buildup manually, use a manufacturer-approved dishwasher cleaner, and allow the machine to dry properly between cycles.

A few minutes of regular maintenance can keep your dishwasher fresher, cleaner, and working properly for much longer.