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How to Clean a Thermos Bottle: Remove Coffee and Tea Stains

A thermos bottle is a convenient way to carry drinks with you wherever you go. If you are a gym rat, you most likely take a thermos bottle everywhere you go to stay hydrated at all times. Others will use a thermos to bring coffee or tea to work with them. In some cases, people will even bring their thermos bottle to the beach so they can enjoy an ice-cold beer when its boiling hot outside.

Whatever your flavor, thermos bottles are incredibly popular and with good reason. They come in different shapes, sizes, colors, and styles, and are an easy way to stay hydrated, as you can easily get the recommended eight glasses of water per day.

If they have a downfall, its that they aren’t self-cleaning, like all dishware, it needs to be cleaned regularly, preferably after each use. Doing so will not only increase its lifespan, but will keep it free of smells, stains, and mold.

While soap and warm water work well for essential cleaning, what do you do when you have coffee and tea stains in your thermos? Or how about if your beverages’ scent is lingering long after you’ve cleaned it? Thankfully, there are ways to restore your thermos to its original condition. Keep reading to discover some methods you might have heard about, and some that you probably didn’t even know existed.


Method 1: Baking Soda & Vinegar

A method as old as time itself, this cleaning solution will always do the trick. It does, however, get very messy. When these two ingredients mix, they cause a reaction which foams instantly (remember those grade-school volcano science experiments?), so make sure you do this in the kitchen sink.

Although you can use any type of vinegar, we recommend using distilled white wine vinegar. This will ensure there is no vinegary aftertaste left behind in your thermos.

Pour half a cup of vinegar into your thermos, and add a tablespoon of baking soda. After the mixture foams up, pour hot water into the thermos. This will distribute the solution evenly inside the bottle and help break things up. Leave the lid off, as the pressure can build up very quickly using this method.

Let it soak for about 10 minutes (longer if you have deep stains). Using anything that is gently abrasive, like a scrub sponge or a toothbrush, you can go to town on the stains, which should be pretty loose at this point and easy to remove.

Method 2: Ice & Salt

Using a combination of ice and salt allows you to use all-natural ingredients to remove stains from your thermos bottle. You will need uneven pieces of ice and large-grain salt for this method. You can break down ice cubes with a food processor/chopper, or go the caveman route and throw a few of them in a Ziploc bag and smash them with a blunt object, like a rolling pin or meat tenderizer mallet. For the salt, we recommend going with rock or sea salt.

Fill up your thermos 1/4 of the way with the smashed ice. Then, add 2 or 3 large spoonfuls of the salt. If you only have regular table salt, just add a few more spoonfuls.

Lock the lid on the bottle and shake. Keep shaking. If you have a really stained bottle, it will take a bit of time, but this combination will remove the stains by exfoliating the interior and leaving it scratch-free.

When you are finished, wash the thermos with warm water and liquid dish soap before rinsing and drying.

Method 3: Dishwasher Detergent

Here’s one you probably never thought of, but it makes so much sense as to why it would work. The powder form of dishwasher detergent can restore your thermos to its original state. This type of detergent spotlessly cleans your dishware in your dishwasher, but the ungodly heat levels these machines produce can damage your thermos. So how can you use the powder to clean your thermos by hand?

You’ll have to do a bit of math here, but add one tablespoon of powder for every liter that your thermos can hold. Add hot water and let the soapy mixture sit overnight. In the morning, you will be able to remove the stains with a scrub sponge. Remember to clean the bottle with liquid dish soap and rinse thoroughly.

Method 4: Lemon Juice

Another all-natural cleaner, the high-acidity level of lemon juice helps remove tough stains. At the same time, its low pH balance and natural antibacterial properties work well as an all-purpose cleaner. After all, lemon juice can erode tooth enamel, so it should easily loosen stains inside your thermos.

Cut up a lemon, and add a few tablespoons of freshly squeezed juice into your thermos. Shake it for 60 seconds to loosen things up, and then use a scrub sponge to give it a more thorough cleaning. Make sure you wash and rinse well as the lemon flavor will be locked into the thermos.

Method 5: Denture Cleaning Tablets

Not only do denture tablet clean stains off false teeth, but they can also clean the stains off your thermos bottle. The secret ingredient here is sodium bicarbonate (aka baking soda). It is present in most denture tablets, but we recommend you double-check your tablets as some brands aren’t made with it.

Similar to the baking soda and vinegar method, this one will cause some foaming. If you are going to clean your thermos with these tablets, make sure you do it in the kitchen sink to localize the mess.

Start by filling up your thermos with warm to hot water – do not use boiling water. Let it sit for a few minutes to loosen up the stained areas, and then add in one or two tablets. The mixture will start to foam, and you should leave it like this for about 30 mins with the lid off.

The denture tablets will not only clean the stains, but they will also sterilize the bottle at the same time. Once the foaming has slowed down, clean the inside of the thermos with a scrub sponge, and then wash it with liquid dish soap before rinsing and drying.

Method 6: Eggshells

This is one of those methods that is almost too bizarre to be true. But yes, eggshells, can remove stains from the inside of your thermos bottle. While its an all-natural, environmentally-friendly process, it certainly isn’t a user-friendly one. To begin, you will have to save your eggshells and dry them out in the sun. Then, crush them up and throw them into your thermos. Fill it up with boiling water, close the lid, and shake it up for a bit. Then remove the cap and let it soak for 15-20 minutes. Finally, wash and rinse the bottle. While it will work, it would be our last choice due to the amount of labor needed for this method.

How to Clean a Coffee Thermos and Get Coffee Smell Out

Most people can’t function very well without their morning cup of joe. For many, their daily ritual includes loading up a thermos full of caffeine to perk them up. Sipping this during your morning commute means you arrive to work bright-eyed and ready to take on the day.

A coffee thermos ensures your coffee stays hot as you sip it to completion. But once it is empty, it just sits for hours until the end of the day, locking in coffee smell, stain, and at times even bacteria, making for one funked-up thermos.

Needless to say, you need to clean it and clean it well. Rinsing the thermos with warm water is a quick fix, but won’t do an effective job. You need to disinfect it. Luckily, we are pros when it comes to clean a coffee thermos thoroughly. Here are two methods you can use to restore your coffee thermos to its original state.

Method 1: Baking Soda & Hydrogen Peroxide

This is a tried-and-true method for cleaning your coffee thermos. The reason being, hydrogen peroxide is a disinfectant and can be found in many household cleaners. It is effective at eliminating a wide range of microorganisms such as bacteria, fungi, and viruses. By combining it with baking soda, which has a soft, abrasive consistency and natural deodorizing nature, you get a powerful cleaner for your thermos.

Making this solution is simple. Pour half a cup of hydrogen peroxide into a bowl and mix in two tablespoons of baking soda. Stir it up and then pour the solution into your thermos. Close the lid, and give the thermos a good shake. Open/remove the lid and let the thermos sit for 30 mins. Once the time is up, rinse it thoroughly. While this level of hydrogen peroxide is pretty much non-toxic, you can never be too safe. For this reason, we recommend you wash the thermos with liquid dish detergent, just for good measure.

Your thermos should now be smell-free, stain-free, and ready for its next use.

Method 2: Antacid Tablets

Any kind of fizzy, antacid tablet will also work at cleaning your coffee thermos. The best part about this method is that antacids contain no toxic chemicals, so you don’t have to worry about potentially ingesting poison even after you’ve rinsed your bottle.

All you have to do is drop 3 or 4 tablets into the thermos and fill it up with hot water. Make sure it is very hot, as this method tends to not work as well with lukewarm water. Leave this combination to soak the thermos overnight, and keep the lid off. In the morning, you can pour out the solution and then wash the thermos with liquid dish soap, ending with a thorough rinse.

How To Remove Tea Stains From A Stainless Steel Thermos

Coffee drinkers aren’t the only ones with problems when it comes to getting rid of stains in their thermos bottle. Tea drinkers experience the same inconvenience, albeit cleaning tea stains doesn’t require an abrasive cleanser or as much elbow grease.

The bad news is the tannins from tea leaves will end up staining the inside of your thermos. The good news is they are rarely permanent and can be cleaned off with mild products.

Here are three foolproof methods to clean tea stains.

Method 1: Soak It

A witch’s brew of sorts, this method combines a bunch of different materials to loosen up the stains. You’ll need to squeeze a quarter-wedge of lemon, a tablespoon of baking soda, a quarter cup of ReaLemon juice, two denture tablets, and two tablespoons of powder dish detergent. Mix it all in a bowl (it will foam, so do this in the kitchen sink). Pour the soak to the halfway point of your thermos, and fill the rest of it up with boiling hot water. Let it sit overnight. By the morning, the stains should be plenty loose for you to scrub off. Finish by washing your thermos with liquid dish soap and rinsing thoroughly.

Method 2: Burn It

This method uses vinegar (which is a mild acid), to burn away the stains. Fill up a spray bottle with distilled white wine vinegar. Spray the inside of your thermos and let it sit. After 10 minutes pass, fill the thermos with boiling water and let it sit again until its cooled. Pour the vinegar solution out and scrub off the stains before giving it a good wash and rinse.

Method 3: Exfoliate It

Our third method is a mixture of corn starch and vinegar to create a gentle exfoliant paste. The corn starch provides some abrasiveness while the vinegar’s acid helps eat away at the stains. Also, because the thermos bottle is made from stainless steel, this method won’t leave any scratch marks behind. After making the paste, apply it to the stains, letting it sit for a couple of minutes so it can work its magic. All that’s left to do is scrub them off, and wash the thermos, so it is ready for its next use.


As you can see, there are many different ways to clean your thermos bottle thoroughly. You should have no problem implementing any of these into your daily routine, keeping your thermos sparkling clean for convenient, on the go drinks.

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