How to Clean a Dishwasher of Mold and Other Suspicious Stains

The essentials

• A dry microfiber cloth
• A sponge
• White vinegar
• A bowl
• Rubber gloves

Optional

An N95 mask if you’re immunocompromised or have asthma

It will take around 15 minutes.

In most cases, what you’re likely seeing in your dishwasher isn’t technically a mold but a yeast. Both are fungi, and several fungal species can be found in trace quantities in tap water throughout the world that can colonize most dishwashers, regardless of geography.

Nina Gunde-Cimerman, a microbiology professor at the University of Ljubljana in Slovenia, discovered a black yeast called Exophiala dermatitidis on the seal around her own dishwasher door, inspiring her team to launch a series of international studies in which she found the same growth and several other types of fungi in dishwashers across 19 countries including the US.

Normally, the heating cycle of a dishwasher would be enough to prevent most fungal growth. But even a small amount of water seepage, often caused by tiny gaps in the door’s seal due to food debris, can allow spores and yeast cells to take hold in the synthetic polymer seal around the cooler, damp edges. Bacteria and fungi growth causes the door seal to become more porous over time, Gunde-Cimerman’s studies found. And fungal cells can disperse throughout your kitchen via steam when you open the dishwasher’s door.

After you don your gloves and optional mask, use a dry microfiber cloth to wipe down the seal. Unlike a regular damp cloth, a dry microfiber cloth captures fungus without spreading it around. Lift up the edges and use your fingers beneath the cloth to get into all of the narrow folds.

Next, soak a sponge in vinegar and wipe down the seal, again lifting up the folds and ridges to get inside of them. Rinse the sponge thoroughly, let the vinegar set for five to 10 minutes so the acid can kill any remaining fungi, then wipe the seal clean.

If you spot some telltale growth in the inner parts of your dishwasher, like the spray arms or racks, follow the steps in our main guide on how to clean your dishwasher and run it on the highest possible temperature or the clean-dishwasher setting if your machine has one. One Wirecutter editor cleans the inside of his by placing a bowl of vinegar in the bottom rack and running a cycle. The force of water from the spray arm coats the inside of the dishwasher with the acid. It’s a commonly known cleaning trick, but be sure to check your dishwasher’s user manual to make sure this is considered safe with your model.

This article was edited by Joshua Lyon, Brittney Ho, and Sofia Sokolove.