how do I remove mold/mildew odor from a bath towel?

A large number of disinfectant sprays are available to consumers that reduce and prevent mildew. Since mildew is a fungal outbreak, any cleaning product that sufficiently inhibits fungal growth, or destroys surface fungi, will probably clear your little problem right up. I use Lysol brand disinfectant sprays to keep things mildew-free around my place (shower curtains get it bad). After treating your towels, be sure to wash them. The disinfectant itself has a very "hospital" smell to it, and I find it unpleasant. Once it has dried, the job is done and you can launder them normally.

A cheaper method for objects like towels is to wash a load of them all together and add a cap of bleach to the water. Bleach kills mildew fungus and will leave less strange odor afterwards. So long as you don't put a huge amount - or add it directly onto the towels, you will be fine lightly bleaching colored towels.

As some collateral advice, I'd suggest that you hang your towels spread as flat as possible. My towels only get mildew odor when they are piled on the floor, or when they are hung all bunched-up or overlapping. If there is adequate ventilation, mildew isn't as quick to form.

Remove Mildew Smell From Towels

If it was me, I may just throw it away, but if you are really attached to that towel, here's what you can do.

Fill your washer to its lowest water level (or just fill the kitchen sink) with hot water, and add a cup of white vinegar. Put the towel in and let it soak for ~30 mins, then add the soap and wash as usual. If that doesn't work, you can try it again, adding slightly more vinegar, a half cup at a time.

You may want to test some diluted vinegar on a corner of the towel, if it's dark, just to make sure it won't bleach the fabric, but it shouldn't.

Good luck!

Wash it by itself with bleach. If the towel is color, use 1/4 the amount of bleach. It may fade a little, but the chlorine bleach will kill the mildew and get rid of the smell.

Dry it with a fabric softener sheet afterwards.

Good luck!

If washing it in hot water does not eliminate the odor, you should throw it away. It is growing bacteria and molds that aren't healthy for you. If it can be bleached, try that--it kills mold.

You can try soaking in bleach water, but it will remove the color (if any) out of the towel... it's probably easiest to just throw it away and buy a new one.

Wash them in hot water. i use Tide with color safe bleach. And here is the real secret--Us OXI Clean. I use oxi with all my laundry. It works great. I left a load of towels in the washer once.

Its not worth the crazy amount of work to get the stink out. If it were white you could wash it in a very bleachy wash by itself, then rinse with vinegar. If its colored there is not much hope. I would chuck it if I were you

Bleach!

If it's white bleach it, if it's colored try washing it with hot water twice and adding some downy to the last wash.