A coffee- or tea-stained cup or mug can look unsightly. Here’s the simple reason and a bunch of easy ways to rid those dark stains.
The brown staining of your cup is from tannin, a plant derivative that’s found in all sorts of products including wood and the things we consume, such as coffee, tea, and wine.
I remember having coffee at my friend’s long ago and seeing the brown stain of my empty mug. The mugs themselves were dark colors so it wasn’t that noticeable at first. My friend would claim the stain adds flavor. I begged to differ, but that never got in the way of our friendship.
What causes the stain? In brewing tea and coffee, we add water. Food scientist, Assoc. Prof. Mercer, explains that the minerals in water, especially calcium, bond with tannins and this is what causes the brown deposits that stain the mug. This staining is worse when using hard-water as compared to soft water.
It helps to have milk in your tea and coffee…
Milk has this protein called casein that bonds with tannins tighter than the minerals in the water and so reduces the deposit on the cup wall. We know from dental research that adding a dash of milk also helps avoid staining of your teeth from drinking tea.
For those of you like me, I’ve found the following work if you’re interested in keeping away those unsightly stains in ceramic mugs.
The most convenient and easiest way to rid brown stains from cups or mugs is the dishwasher.
Putting tea cups and coffee mugs through the dishwasher after use each time will bring them up sparkling and help avoid those stubborn tea stains (or coffee stains).
Stains will never get a chance, unlike any regular hand washing with dish soap. But if for some reason this fails for you, look at the quality of the detergent you’re using, is it good enough? and the dishwasher cycle, is it hot enough?
Note: Some mugs, like the Ember with its sensors, travel mugs, and some that are decorated, aren’t designed to go through a dishwasher. I recommend hand washing these.
Soak in bleach and water
This was the approach used in a restaurant where I once worked. It worked a treat! Once a week, we’d remove coffee and tea stains from cups and mugs by soaking them in a large container of cold water with a good dash of bleach for an hour or two. Tip: Wash with dish soap in warm water to get rid of any coffee residue before soaking.
Is bleach one of those harsh chemicals? Bleach probably isn’t the most eco-friendly agent for removing tannin stain, and especially not recommended for removing stains from mugs made of metal or stainless steel, because there’s this chemical reaction that happens.
Cleaning stains from special mugs
You might be like me and have celebration mugs or other special ones with with exterior embellishments. Often they’re gifts.
I found dishwater cycles and detergents are harsh on these. Gentler cleaning options for removing stubborn stains from inside these special cups include non-toxic vinegar, salt, and baking soda methods.
Below are my stain removal tips on how to clean cups and mugs the eco-friendly and non-toxic way to rid tea or coffee stains without losing the ‘specialness’ details.
More ways for removing tea stains and coffee discoloration from mugs and cups…
Rub with salt or sugar
Dampen a toothbrush or soft cloth in cool water and dip it in cooking salt or sugar. Then rub the inside of the mug or cup until you no longer see any color coming off and the stain is gone. Rinse with clean plain water and dry as usual.
Tip: Don’t use boiling water. You don’t want hot water dissolving the salt (or sugar) when what you really want are the granules to go to work. You just need a bit of water to dampen the cloth or brush.
Rub with baking soda (Bicarbonate of soda)
Moisten a soft cloth, soft sponge, or paper towel in warm water. Squeeze out excess water. Wrap the damp cloth or towel around your index finger and dip it in baking soda.
Then rub the inside of the mug or cup with your wrapped finger to remove the tannin stains. Repeat if necessary to remove any remaining stain. Rinse and dry as usual.
With baking soda, or sodium bicarbonate, you can clean the most difficult stain from a stainless steel mug safely as well as from your china cup or a ceramic or porcelain one. Baking soda is also useful as a carpet cleaner. It can absorb carpet stains and freshen the area as deodorizes.
For scratchless cleaning
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Use White vinegar
Dip the tip of a soft cloth or soft sponge in white vinegar and rub it in a circular motion over the stains. Use a bit of elbow grease. You’ll notice the stain transfers onto the cloth, more so if it’s a white cloth.
Repeat as needed until the stains are removed. Rinse with clean water and dry.
Vinegar is a non toxic cleaner that can be used for cleaning tea stains from ceramic mugs (not recommended for metal). Ceramic (unlike metal) does not react with acidic ingredients, and so using vinegar on ceramic mugs is a fairly safe option. The same applies with lemon juice…
Use a cut lemon wedge to rub over the inside of the cup to remove the stain. Also, after you’ve squeezed out the juice for a recipe you can use what’s remaining to clean away the stain.
You can use this simple cleaning method of rubbing the inside of the cup with the cut-side of the lemon or use fresh lemon juice in place of vinegar in the method listed above.
This is simple. Grab hold of a magic eraser and use it to rub away the staining inside the mug or cup. Magic it is! A Magic Erasor sheet type is perfect for fitting inside a mug. Tip: Sometimes I add a couple of drops of water to make it even easier.
Magic Eraser Sheets
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Just like stains on teeth, you can remove coffee or tea stains with denture cleaning tablets. One denture tablet left in a cup of water does the trick…
Just fill your cup (or mug) with cold water, add a tablet, and let sit for 3 to 4 hours. It’s perfect for one or two, but for several cups/mugs you’ll need a bunch of tablets for this cleaning solution. Another problem is the time it takes to work doesn’t help if you’re time-limited.
I hope you found this article helpful. I clean most of my cups and mugs in the dishwasher because they sparkle every time. But, what I found with my customized mugs, the dishwasher would start to erase the special markings. They’d fade or wash away over time. I now hand-wash these with soapy water so I can retain their ‘specialness’.
When tough stains build up, my favorite method to get rid of them is to use baking soda with a damp sponge. Why? Because, it’s also a good all round cleaner and deodorizer, and it has many purposes around the kitchen and home in general.