The culprit behind stiff towels and a sour smell in the laundry room is usually deodorant.

The antiperspirant kind is the worst offender because it is designed to stick to skin, and it sticks to fabric and drum walls exactly the same way.

Where it comes from

You apply deodorant, it transfers to the inside of your shirt, and the washing machine does not fully dissolve the waxy component at low temperatures. Warm washes and cold washes both leave residue behind, just at different rates.

Over time it coats the drum, the detergent cannot work through the film, and everything you wash comes out slightly dull.

I ignored a grey film inside my drum for months. Then the towels started coming out stiff and faintly sour and I finally connected the two.

The cleaning cycle

1. Run the washer empty on the hottest setting it has.
2. Add two cups of white vinegar to the drum directly.
3. Add half a cup of baking soda to the detergent dispenser.
4. Let it run the full cycle, then wipe the drum with a clean rag while it is still warm.

The rag comes out grey. That is the film you have been washing your clothes in.

Fix the source

Let deodorant dry before you dress. Two minutes is enough. Damp deodorant transfers almost completely to fabric.

Turn shirts inside out before they go in the hamper. The deodorant side faces out, water hits it first, and far less residue survives.

For the front loaders

Do not forget the rubber gasket around the door. That is where most of the buildup hides and where the smell comes from. Wipe it with a vinegar soaked rag and check the folds.

Run this cleaning cycle once a month. It takes 45 minutes and it prevents a repair call.