The Ridiculously Easy Way to Clean Coffee Stains from White Mugs

published Apr 18, 2022
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Woman holding coffee mug
Credit: Getty Images/ Jamie Grill

Some things look better with a bit of wear and tear — coffee mugs aren’t one of them. As a former barista, I can tell you, there’s always (at least) one stubborn mug in any coffee shop that feels destined for the dish pit, no matter how many times you scrub it or run it through the dishwasher. Even though I knew these mugs were clean, the rings and stains from coffee drinks past would make me immediately pass on using these mugs for customers.

It’s inevitable, though: Most white or light-colored mugs will exhibit some rings and stains. Why? Because coffee is full of oils and lipids, which contribute to the overall body of your drink but leave a noticeable ring on the interior. Sometimes, these stains are easy to clean with soap and elbow grease. But sometimes, you need a more serious solution to get stubborn stains out. 

At home, I found myself in that second situation. So I decided to try soaking my cups in non-toxic Dri-Pak Soda Crystals. I had heard these crystals were a popular solution in England (and have been for generations), so I thought I’d give this cleaner a try over here in the states. It was easy enough to get my hands on a bag, thanks to Amazon.

Credit: Ashley Rodriguez
A bag of British-made Dri-Pak ready to be used for cleaning.

Admittedly, I didn’t know much about Dri-Pak, so I had to dig a little. Turns out, it’s a UK-based family business that’s been around since the ’60s. The company makes lots of products, with the Soda Crystals being one of the most popular and versatile. Soda Crystals used to be called Washing Soda and are the non-scientific name for sodium carbonate decahydrate (say that five times fast). The stuff is soluble in water (in fact, it’s meant to be mixed into water) and acts as a detergent. To nerd out for a second: It makes things like fats and oils “water-miscible” or able to combine to form a homogenous mixture rather than repel one another like oil and water usually do. It can be used to wash your laundry, wash your laundry machine, clean pots and drains, remove moss from patios, and more.

To clean coffee mugs, all you have to do is shake a little bit of the crystals into said cup, add in some hot water, let the solution sit for at least 30 minutes (preferably overnight), and then you can wipe the stains right off. 

I put on my Science Hat and picked out two mugs to see how the crystals handled fresh stains and older, more set-in stains built up over years and years of use. I grabbed a mug from a cappuccino I drank a few hours ago sitting in my sink. I also grabbed my favorite mug, which had a decent number of rings and stains, particularly in the fold on the side (I love handcrafted pottery!). I wasn’t 100 percent sure how much cleaner to use, so I started with a teaspoon for both mugs, and let them sit with hot water for a half-hour. 

Credit: Ashley Rodriguez
Here's the cappuccino mug: the crystals did the tough work!

For the cappuccino-stained mug, the crystals did the trick. All of the coffee stains came right off and required minimal scrubbing. I went in with my hands to get some of the old coffee off, but I didn’t even need to grab a sponge or anything more abrasive to get the mug totally clean. 

Credit: Ashley Rodriguez
The mug sitting with the solution. You can see it's already working!

As for the other mug, my favorite mug, the crystals effectively cleaned some of the coffee stains, but didn’t get the deeper stains I was hoping to remove. So I tried again, this time leaving the solution to sit on my counter overnight. 

The deep-seated stains on the top and sides melted away the second time around. I still had to scrub the sides to lift some of the more aggressive stains, but I noticed the rings towards the top were gone, and I didn’t see any stains in the fold of the mug. 

Overall, I won’t be cleaning my mugs every day with Soda Crystals, but they work well and are highly effective for a deeper clean once in a while. My favorite cup now looks better than brand new!

How do you clean your coffee-stained mugs? Tell us your miracle solutions in the comments below.