How often should you wash your office mug?

What do scientists have to say about this? It’s hard to believe they would overlook such an essential part of our workday as drinking coffee or tea.

You can’t get through the office without a cup in hand. The beverages we pour into it help us gather our thoughts and perk us up. Plus, a cup with a unique design can showcase our individuality.

A cup, or as it’s also called—a mug—takes care of us. But do we return the favor? In other words, do we wash it regularly?

It turns out that there are as many ways to handle an office cup as there are people. Some wash theirs daily, others rinse it after each use, some remember it only at the end of the workweek, and some (imagine!) never wash it at all.

According to a recent survey of over 2,000 British adults, most people wash their cup right after finishing their tea or coffee. Those who wash their mug after multiple uses are in the minority. Meanwhile, three percent of respondents don’t think it’s necessary to wash it at all, as reported by IFLScience. For this small group of office workers, cup hygiene seems like an alien concept.

Neglecting to care for a mug often leads to fuzzy patches of mold growing at the bottom. This should serve as a wake-up call, even for those three percent of messy individuals.

Expert Opinions

“If I took a sample from a typical unwashed coffee cup, I would certainly find microbes in it. But remember, the vast majority of microbes come from the person who used the cup,” noted Professor Jeffrey Stark, an infectious disease specialist at Baylor College of Medicine in Houston, Texas.

Professor Charles Gerba, a microbiologist and environmental health expert at the University of Arizona, is equally intolerant of dirty mugs. He states, “About 90 percent of office cups contain harmful microbes, and 20 percent harbor fecal bacteria.”

Both professors suggest that any unpleasant bacteria lurking in your mug could actually result from improper washing.

The issue is that the sponge in the break room can harbor more bacteria than anywhere else in the office, according to Professor Stark. It’s used to clean a variety of items, often remains damp, and isn’t replaced frequently. As Jeffrey Stark aptly put it, “Most people would call that disgusting.”

But is it really better to leave the cup unwashed? Most office workers would disagree with such a radical approach.

Scientists recommend using soap, hot water, and paper towels for cup hygiene. After thoroughly washing with water and soap, the mug should be dried well to keep it dry until the next cup of tea or coffee.

Experts insist that this procedure should be repeated after each use.