The American Cleaning Institute (ACI)

Ask ACI: Coffee Cup Cleaning


Q: I've given up buying coffee in the morning in favor of bringing my own in a travel mug. However, the cup sits in my car all day and doesn't get washed until late at night. The inside is a little grungy. How do I get it really clean? 

A: There are several ways to remove coffee stains. You may have to experiment to see which one works best on your particular travel mug. Since soaking is easier than scrubbing, try one of these methods first: using chlorine bleach, soak the mug overnight or fill the mug with boiling water, add two spoonfuls of dishwasher detergent and soak overnight. If neither method works, mix one part dishwasher detergent with three parts water and a splash of white vinegar. Let it sit in the mug for about an hour. Scrub with a nonabrasive cleaning pad and rinse well.