So… let’s face it. We’ve all done this at least once: loaded up the washing machine, gone off to do something else, then come back the next morning, wondering why our clothes smelled like they’d been sitting in the basement for weeks.
And yes, besides being an incredibly frustrating thing to forget, wet clothes can create a serious problem. If you’re not careful, leaving your clothes in the washing machine too long creates the ideal environment for mildew or mold to grow, which is not only smelly but potentially unhealthy.
So… how much time do you have? In most cases, you’ll be okay for 8-12 hours. However, the actual amount of time will depend on several factors.
Answer quickly: how much time do I have?
Ideally, you should get your clothes into the dryer or put them on a drying rack immediately. However, sometimes things just don’t work out the way you plan. Generally speaking, most laundry professionals agree that it’s okay to leave clothes in the washer for 8-10 hours without creating an unpleasant odor.
You may get away with leaving clothes in the washer for 12 hours, however, if you check them first to see if they still smell fresh, you’re likely to be okay. Dry them in the dryer, and you’re good to go.
However, if you find yourself waiting longer than 12 hours, and/or in a warmer/humid area, there’s a good chance that the sour/mildew smell is going to begin to develop. At that point, it’s usually time to re-wash.
Here’s a quick chart to help you decide:
Less than 8 hours: fine
8-12 hours: sniff test + check conditions
More than 12 hours: warm room/overnight = rewash safest
Why wet clothes develop odors (science in simple language)
Washing machines are petri dishes for bacteria. They’re dark, wet, warm, and low airflow. Plus, residue from leftover soap and debris on your clothes provide bacteria with a three-course meal.
Musty/sour smells are the first red flag. Even though these odors may not be harmful to most people, they indicate that mildew or mold has started to grow. Mildew/mold attach themselves to fabric extremely well. Front load washers seem to trap moisture more than top load washers, therefore creating this problem more often.
Conditions that affect the time frame
Room temperature/humidity
The warmer/more humid the laundry area is, the faster odors will appear. Heat/moisture are like rocket fuel for microbial growth.
Type of washer
Front loading washers seem to seal tighter than top loading washers, trapping all that damp air inside. Unless you crack open the door after each wash, clothes may develop funky smells before expected.
Size of loads/fabrics
Bulkier loads containing towels, sweatshirts, jeans etc., take longer to dry and create an environment where mildew thrives. Athletic gear/synthetic fabrics also retain body oils/odors which speeds up development.
Were the clothes dirty?
If your clothes were extremely sweaty/dirty (example post gym wear/kids muddy clothes), you have given bacteria a head start.
Decision guide: do you really need to rewash?
To make things easy for me, here’s my go-to method:
Smell them. If they smell normal, good luck. Just dry them.
If there’s a slightly “off” smell (not quite mildew, but not exactly clean either) you might get away with a quick rinsing/spinning cycle, or a short wash.
However, if they hit you with that strong musty/sour smell, don’t ask yourself about it. Rewash with detergent. A regular short cycle should take care of it.
If they sat for 24+ hours, or if you notice any discoloration/weird spots, rewash with hot water if the fabric label says it’s okay.
How to fix musty laundry
Ugh, so maybe you left them too long, and now they smell like the basement. No panic. There is hope. Re-wash ASAP. If the smell persists, try adding half a cup of baking soda to the wash or white vinegar during the rinse cycle. Please note: vinegar does not play nice with some delicates.
Make sure the clothes dry completely afterwards. Sunlight can help kill odors naturally. Oh, and use less detergent next time. Surprisingly, using too much soap leaves residue behind, which actually makes smells worse over time.
Preventing it next time
Don’t want to experience the smell again? Set a phone alarm or turn on your washing machine’s end-of-cycle chime if it has one. If you know you won’t be around to transfer the load right away, use the delay-start feature to better time it.
Don’t overload your washing machine. Ideally, you want clothes to rinse and spin as clean as possible, leaving minimal amounts of water behind. Between loads, leave the washing machine door/lid cracked open to let it air out, especially for front loaders. Give the gasket a wipe every so often.
Run a hot “clean cycle” once per month, or use a washing machine cleaning tablet to clear out hidden build-up that creates odors.
Frequently asked questions
Q1: Is it safe to leave clothes in the washing machine overnight?
If it’s under 8-12 hours and your clothes still smell fresh, you’re likely in the clear. If they smell musty, re-wash.
Q2: Can leaving wet clothes for too long damage fabric?
It won’t ruin your clothes, but it can cause wrinkles, fabric wear, and even dye transfer when mixed loads are ran.
Q3: What if the clothes dried inside the washing machine?
If they dried clean and don’t smell bad, you got lucky! Just steam or lightly re-dampen and put them in the dryer to release wrinkles.
