Towels smell musty only when wet?

I have some towels that smell musty only when wet. They were damp for a couple days and started smelling musty, when I washed them they smelled fine, but as soon as they get wet 30 seconds later they smell musty again. I don’t see mold on them so I don’t understand why. Anyone know why it only smells when wet? I am deciding if I need to throw them away.

Are you on well water or city water? Wash them with a full cup of bleach.

city water

Do you throw them in the dirty laundry hamper wet? That could be the problem if you do. Hang wet towels to dry before stuffing them in a hamper.

Cider vinegar works too.

I would wash the towels in a heavy bleach wash. Wash the the hamper with a bleach solution. Air dry all of it, in the sun if possible. If they still smell musty then toss 'em.
Bleach is cheap.
Oh yeah, do you have a top load or front load washer? Front loaders have odor issues.

I guess I’d agree, but I think front loaders get issues because people don’t leave the door open after a load, so mold might grow inside the damp chamber. It’s pretty natural to leave a top-loader’s lid open in between loads, so perhaps they tend to dry out in most circumstances = no mildew.

When this happens to me, I use the ultra hot clothes washer setting. It works wonders, but I realize not all washers have this.

You could wash them at a laundromat and see if its a washing machine problem.
Are the towels 100% terry cotton or a synthetic blend. I bought some dish towels that were microfiber they never really came clean. They got sent to garage quickly.

I use white.