One thing you do after every load quietly grows mold in your washer: the 2-second move to stop it
Your washer just ran a hot cycle for the better part of an hour (about 60°C water on the hottest setting, roughly 140°F). Everything came out smelling clean. So it feels a little insulting when, a few weeks later, your fresh laundry starts carrying a faint sour smell you know wasn’t there before. You sniff a folded shirt. Nothing. You sniff the inside of the drum. There it is. That damp, musty, gym-bag kind of smell, coming from the one machine in the house that’s supposed to be the cleanest.
If you own a front-loader, you’re not imagining it, and you’re not alone. GE Appliances said in its own press release that 46 percent of front-load owners named mold or odor as their biggest complaint, and one in two eventually went back to a top-loader because of the smell. That’s not a small design flaw. That’s roughly half the people who buy one.
And nobody tells you this when you’re standing in the store: the smell isn’t really from your clothes, your detergent, or your water. It comes from one small thing you do every time you finish a load. It takes about two seconds. Almost everybody does it. And it’s the single biggest reason your washer smells the way it does.
What’s really going on inside the drum
A top-loader has a big open lid. After a wash, air moves in and out, and everything dries. A front-loader is different. The door pulls tight against a thick rubber ring around the opening (the “gasket,” the part your hand brushes when you load clothes in). That rubber ring is what stops water from spilling on your floor when the drum spins. It has to seal tightly. That’s its job.
But when the wash ends, all that water and heat doesn’t just disappear. Small puddles get trapped in the folds of that rubber ring, especially at the bottom, where gravity pulls the water down. Soap residue sticks to the rubber. Lint from your clothes gets stuck in the folds. Skin flakes, body oils, and fabric softener film cling to the drum walls.
Then the last load comes out, and the door swings shut.
Whirlpool’s own care guide says it out loud. In the company’s official cleaning instructions, the rubber ring around the door traps moisture, and that turns it into a perfect place for mold and mildew to grow if it isn’t dried out. LG’s US support page says the same thing: if the door stays closed after a wash, the moisture inside can’t escape, and mold starts forming inside the rubber ring, especially in warm or humid weather.
This isn’t a smell problem, it’s a living-things problem
Scientists have actually looked at what grows inside home washers, and it’s not pretty. A 2024 review in the medical journal Antibiotics found that the rubber ring, drum, and soap drawer inside household washers grow slimy layers of bacteria and mold called biofilms. Think of a biofilm as a tiny slime city that sticks to surfaces and gets harder to scrub off the longer you leave it alone.
A separate 2025 study in the journal Frontiers in Microbiology looked at exactly which bacteria and molds live in those layers. The researchers found common indoor molds (the same families that grow on damp bathroom walls) and several bacteria that live on human skin. A few of them can cause problems for people with weaker immune systems, like the elderly, the very young, or anyone recovering from illness.
That’s the “sour” you’re smelling. It isn’t dirty laundry. It’s a tiny ecosystem that moved into the warm, wet, food-rich space your washer becomes every time the door shuts on the day’s last load.
And this isn’t a rare thing. It’s how sealed front-loaders behave when nobody helps them dry out. The industry knows. That’s why GE Appliances launched a whole washer line called UltraFresh in December 2019, sold on the promise that a built-in fan would dry the drum for you so you could skip the small daily habit most front-loaders quietly need. GE’s own announcement said what most brands had been quiet about for years: the sealed, humid inside of a normal front-loader is a mold problem waiting to happen, and owners were tired of the small daily upkeep it really takes to keep it clean.
That upkeep is the fix. It costs nothing. It’s in the manual of every major brand. And almost nobody does it.
The two-second move nobody bothers with
The fix. And you’re going to be a little annoyed at how simple it is.
- Leave the washer door open after your last load. Not wide open. Just cracked, about 4 to 8 cm (a few inches), enough for air to move in and out of the drum. That’s it.
Consumer Reports says it plainly: if young kids aren’t in the picture, keep the washer door propped open between loads so the inside can dry out. LG’s own help page tells owners the same thing, adding to also pull out the soap drawer so the moisture in there can escape too. Whirlpool’s guide agrees. Three of the biggest brands, plus the country’s biggest consumer testing group, all pointing to the same free, effortless habit.
Why does something so small do so much? Mold doesn’t need much to grow, but it does need one thing: moisture that doesn’t leave. Take that away and you take away the whole reason it’s there. A cracked door dries the drum and rubber ring in a couple of hours, instead of letting them stay damp until the next load.
What to actually do, step by step
The full version of the fix. All free, none of it more than a minute.
- After your last load of the day, leave the door cracked open a few inches (about 4 to 8 cm). Overnight is best. If your machine has a small magnetic clip to hold it ajar, use it.
- Wipe the inside of the rubber ring with a dry cloth, especially along the bottom curve where water pools. Gently pull the fold back and dry underneath too.
- Pull the soap drawer open a few inches and leave it that way, or take it out and rinse it if you can see gunk on it. Trapped moisture in the drawer feeds the same slime.
- Don’t leave wet laundry sitting in the drum. Move it to the dryer or line as soon as the cycle ends.
- Use less liquid detergent than the bottle says, or switch to a high-efficiency powder. Leftover suds are literal food for the slime.
Two important things before you go do it
- First, if you have young kids at home, don’t just leave the washer door open and walk away. According to Consumer Reports, the US Consumer Product Safety Commission has recorded at least three child deaths and about 3,000 ER visits involving kids age 5 and under and washing machines since 2014, and two of those deaths involved children climbing into open front-loaders. If little ones can get near the washer, lock the laundry room, turn on your washer’s child-lock setting, or add a simple outside latch.
- Second, if your machine already smells sour or you can see dark speckling in the rubber ring, opening the door alone won’t fix what’s already there. Wipe the ring with a warm-water cloth and run your washer’s built-in cleaning cycle with the cleaner your manual suggests. Then start the door-open habit going forward so it doesn’t come back.
You paid for a machine that uses less water, less energy, and is gentler on clothes. You didn’t pay for one that smells like a wet basement. Close the door on the wash. Leave it open on the dry.
Sources: (1) Consumer Reports on front-load washers; (2) Whirlpool official gasket care guide; (3) LG US support on front-load washer gasket mold; (4) GE Appliances UltraFresh press release; (5) Antibiotics 2024, washer biofilm and malodour review; (6) Frontiers in Microbiology 2025, household washer microbial ecology; (7) Consumer Reports on child safety and front-load washers.