You never have to wash your office coffee mug - ever again.

This post is going to make a lot of people angry.

A coworker of mine who sits behind me, for example, and has anti-bacterial handwash on her desk and in her handbag and screamed like she was in a horror movie once when she saw a ring of crusty tea in a “clean” mug, she’s going to hate me for writing this post. We’re friends, despite our differences in cleaning habits.

You see, washing your coffee mug at work is not actually essential for hygiene. Science says so.

That’s right. There is finally a verdict. An objective learned verdict. That decides, once and for all, the question that separates the two types of people in the world: The mug washers and the non-mug washers.

Infectious-disease expert Jeffrey Starke told Heidi Mitchell of The Wall Street Journal that re-using the same coffee cup, without washing it, is healthier and less germy than using the communal sponge and dishwasher to clean out the cup between drinks.

“The sponge in the break room probably has the highest bacteria count of anything in the office. Most people would call that gross,” Starke said. (He was the director of infection control at Texas Children’s Hospital for 22 years, so he should know).

The surface of a coffee cup isn’t particularly conductive to harbouring germs, Starke explained. And, the germs that mug does carry Well… They’re already yours. 

“If I went and cultured the average unwashed coffee cup, of course I’m going to find germs,” Starke said. “But remember the vast majority came from the person who used the cup.”

His only advice re. re-using coffee cups?

Don’t share your cup (remember what your mum used to tell you about sharing cups and getting tonsillitis?)

And don’t leave milk and sugar in the bottom of the mug over the weekend. The germs won’t be so friendly after that.

Case closed (don’t get angry at me colleague who sits behind me – it’s science).