She looketh well to the ways of her household and eateth not the bread of idleness.  Proverbs 31:27

There are many things that can contribute to sour towels.  Letting them sit in the washer too long before putting them in the dryer can cause them to sour.  Especially the big fluffy bath towels that absorb a lot of water.  Also, using too much liquid fabric softener can cause towels to sour.  Below is the remedy that I have used to freshen towels.  It make take several attempts depending on how sour or how long the towels have been sour.