Courtney and I use our Zojirushi stainless steel mugs every day. I have the 16oz model with SlickSteel interior and use mine for coffee while she has the 20oz model with non-stick interior which she uses for water since we have a professional liquid spiller on duty 24/7. We LOVE these vessels as they keep our drinks hot for hours or cold for days and keep spilling to a minimum. The only complaint I have about the Zojirushi mugs can’t really be registered as a formal complaint as it all has to do with how I care for my mug (or the lack of care in this case). I tend to leave my empty or nearly empty mug in my bag or on the counter overnight during the week more often that I’d like to admit. Recently I noticed that my (artis-anal) coffee was sour and the inside of my mug was coffee stained and was no longer that beautiful polished chrome steel that I originally unpacked. I turned to the internet and found I wasn’t alone. While the image below is 10 stages beyond what the inside of my mug looked like, I was seeing similar staining as the bottom of the mug in this picture.

One heck of a stained Zojirushi mug Source: Tested

“That’s dis-gusting”.

I know you’re thinking it and I couldn’t agree more. With that said there is the issue of how to clean these mugs when they get stained. I started to take a crack at it and found myself getting nowhere when I tried due to two factors.

Washing the center and bottom sections of the inside of these mugs is a major PITA. I broke a spatula handle by applying more pressure than it could handle in my attempts to clean it.
The stain can become partially infused and layered onto the stainless steel of the mug.

After 30 minutes of dish soap, paper towels, elbow grease and scalding hot water I had barely made a dent in the overall staining and wanted to give up on trying. Then I realized I had a cleaner that no stain or dirt is immune to and that it just might be worth a shot to bring out the big guns. Yes, of course I’m referring to an extra strength Mr. Clean Magic Eraser! I gave it a dunk in scalding hot water and forged ahead full strength in my attempt to restore my beloved coffee mug as replacing it isn’t an option due to it’s unique branding.

RelayFM Zojirushi

After another 45 minutes of continual washing, rinsing and repeating I was able to get my mug back to full health and beauty. This worked like a charm and was a mere dollar worth of hardware[1].

So fresh and so clean

As long as you follow up with a dish soap hand wash and multiple rinses you should be golden using this method if your mug has gotten stained from long term use. I’m no longer risking this possibility and am cleaning my mug nightly which takes a mere 60 seconds of my day to do. I’d recommend doing the same.

If you don’t count the spatula that gave it’s life in service of a greater good. ↩