How to clean a coffee thermos

Here’s How to Clean a Coffee Thermos [5 Easy & Proven Ways]

If you enjoy sipping your favorite beverage on the go, it must be your coffee thermos is your loyal companion. It keeps your drink at an optimal temperature and retains its original flavor throughout the day. Yet, your portable container can also trap smells and stains due to its specific design. Do you know how to clean a coffee thermos?

  1. Dissolve a denture-cleaning tablet in your thermos
  2. Leave it to sit there for several hours
  3. Scrub the inside
  4. Flush the whole thing with clean water

Alternatively, you can also follow these steps:

  1. Add 2 tablespoons of sea salt and some crushed ice into the thermos
  2. Shake it vigorously a few times
  3. Rinse away any residue with clean water

Discover more tried and tested cleaning methods below and ensure your fresh morning batch of coffee remains yummy until the end of the day.

5 Super-Easy Methods for How to Clean a Coffee Thermos!

How to clean a coffee thermos, denture tablets

1. Denture Tablets

What you’ll need:

  • 3 to 6 cups of hot water (depending on the capacity of your thermos)
  • 1 to 2 denture tablets
  • Bottle brush


  1. Fill the thermos halfway up with lukewarm or hot water
  2. Let the water sit inside for 10 to 15 minutes
  3. Add denture tablets and close the lid
  4. Wait for 2 to 3 hours for the mixture to soften any stains
  5. Use a bottle brush to scrub away any residue from the walls of your thermos
  6. Rinse with clean water several times to make sure you’ve eliminated the denture cleaner
  7. Turn the thermos upside down and let it dry without the lid

How to clean a coffee thermos, sea salt

2. Salt and Ice

What you’ll need:

  • Several ice cubes
  • Kosher or sea salt.


  1. Crush several ice cubes so that you fill a quarter of your thermos’ overall volume
  2. Sprinkle 2 to 3 tablespoons of sea salt (2 tablespoons will work just fine for smaller thermos models)
  3. Close the lid and shake the thermos as if you’re shaking a cocktail shaker
  4. Empty the thermos and flush with water
  5. Let it dry with the lid off

How to clean a coffee thermos, baking soda

3. Vinegar and Baking Soda

What you’ll need:

  • ½ cup of distilled white vinegar
  • 1 тablespoon of baking soda
  • Hot water
  • Bottle brush


  1. Place the thermos above the sink and add white vinegar and baking soda
  2. The mixture will create a fizzing chemical reaction so wait until it calms down a bit
  3. Add hot water (enough to fill the entire thermos)
  4. Leave the thermos for 10 to 15 minutes in the sink with the lid open
  5. Use a bottle brush to remove any buildup from the walls of your thermos
  6. Rinse with hot water twice to ensure your coffee doesn’t smell like vinegar

Additionally, make sure to use hydrogen peroxide instead of the vinegar and baking soda mixture if you are dealing with tougher stains.

This is a strong cleaning agent that can sanitize your coffee thermos but make sure to rinse it well before storing coffee in it.How to clean a coffee thermos, dishwasher powder detergent

4. Dishwasher Powder Detergent

What you’ll need:

  • 1 tablespoon of dishwasher powder
  • Hot water
  • Bottle brush


  1. Pour 1 tablespoon of the dishwasher powder into the thermos
  2. Pour 2 to 3 cups of hot water into your thermos
  3. Close the lid and shake it for 30 seconds
  4. Open the lid and fill the thermos with hot water all the way up to the max line
  5. Leave the thermos open overnight
  6. Give it a good scrub in the morning
  7. Rinse the thermos with water and let it dry naturally

How to clean a coffee thermos, lemon juice

5. Lemon Juice

What you’ll need:

  • 1 lemon
  • Bottle brush


  1. Make a 50:50 cleaning solution of lemon juice and water and pour it into the thermos
  2. Leave the mixture to sit there for 30 minutes
  3. Use a bottle brush or sponge to remove build-ups and stains from the walls of your thermos
  4. Pour the mixture out and rinse the container with water two or three times to remove any lemon scent that might be present

How Do You Clean a Stainless Steel Thermos?

Simply use some vinegar and baking soda to remove any stains and grime from your stainless steel coffee thermos.

And the great thing is that this mixture works brilliantly for removing tea stains as well.

Alternatively, you can make a mixture consisting of 2 tablespoons of baking soda and ½ cup of hydrogen peroxide.

How Do You Get the Smell Out of a Coffee Thermos?

  • Add 1 tablespoon of baking soda into the thermos
  • Pour hot water over the baking soda
  • Close the lid and shake the thermos for a couple of seconds
  • Let it sit for about 1 hour before rinsing

However, a mixture consisting of 1 tablespoon of soda, apple cider vinegar and a cup of water is even more efficient when it comes to dealing with unpleasant smells in your coffee thermos.

Add this mixture into the container and let it stay there for a while.

And as always, rinse away with clean water before the next use to get rid of any leftover smells.

This should be enough to remove any unpleasant scents but be careful to clean your thermos regularly if you want to ensure your coffee is odor-free!

Still, we wouldn’t recommend using dishwashing soap and water for eliminating bad odor from your coffee thermos.

Instead, go for natural solutions such as soda and apple cider vinegar!

Why Does My Coffee Taste Like Soap?

Because you haven’t properly rinsed your coffee thermos the last time you used soap for washing it!

Or in other words, if you haven’t rinsed any of the cleaning agents well, it’s highly likely that your coffee would carry a soap-like taste.

That’s why you should always rinse the thermos with clean water two to three times after using any chemicals for cleaning it.


There’s no doubt that your coffee thermos will develop stains rather quickly if you continue using it every day, but only clean it once in a blue moon.

It’s especially and if your water is hard as hard water stains can potentially lead to headaches and make your coffee taste bad.

Luckily, you can try any of these 5 neat methods about how to clean a coffee thermos to get rid of that stubborn coffee grime that simply wouldn’t go away by only rinsing it.

Now – do you personally clean your coffee thermos after each use?

And does your coffee change its flavor after being stored in a thermos for a couple of hours?

We’d love to know so don’t hesitate to leave your answers in the comment section below!

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