How To Remove Coffee Stains From Stainless Steel Thermos

You love your coffee drinks and can hardly go a day without them! You take it with you to work in your handy stainless steel thermos, but unfortunately, you do not have the time to clean it as often as you like.

Because of this, it can cause your coffee to become bitter tasting as coffee stains have built up in your stainless steel thermos.

We can help. We have done the research, and it is time to deep clean and learn how to remove coffee stains from your stainless steel thermos.

What You’ll Need

Now that you have everything you need continue reading for step-by-step instructions on how to remove coffee stains from stainless steel thermos.

1. Pour Baking Soda into Your Thermos

Pour about two tablespoons of baking soda into the stainless steel thermos.

You can choose to use more or less baking soda, depending on the size of your stainless steel thermos.

2. Pour In Boiling Water

Be sure to boil enough water to fill your entire stainless steel thermos.

Pour in the boiling water into your stainless steel thermos to the top, but not too much that you cannot twist on the lid.

3. Let the cleaning mixture Sit

Now let the baking soda and boiling water mix sit in the stainless steel thermos.

Twist on the lid, but not all the way.

You want to make sure you do not pressure to build up from the boiling water and baking soda. 

The coffee stain build-up in your stainless steel thermos will determine the length of time you let it sit.

The wait time can be as short as an hour and a half or as long as 12 hours.

It is essential to let it sit for as long as possible so that the baking soda can work to break down the acidic coffee stains. 

4. Pour Out the cleaning Mixture 

Once you have let the baking soda and boiling water mixture sit, you can begin to pour it out into your sink.

Pour out small amounts at a time and shake the bottle with the lid on in between.

Doing this will help dislodge any coffee stain bits that remain attached to the stainless steel thermos.

5. thoroughly Scrub your thermos

Once you have poured out all of the baking soda and water mixture, take a scrub brush that can fit into your stainless steel thermos.

I recommend grabbing this Holikme 5 pack Deep Cleaning Brush Set off of Amazon.

One of the five scrub brushes is perfect for the slender stainless steel thermoses that coffee drinkers love, plus it gets excellent reviews.

Begin to scrub the walls and bottom of the stainless steel thermos to remove any of the stubborn coffee stain remnants. 

Rinse out the stainless steel thermos with clean water and let it dry.

6. Repeat If Necessary

If you still notice coffee stains in your stainless steel thermos, repeat the process above until it is removed.

Consider adding more time to your waiting period.

Doing this will help to allow the baking soda and boiling water to act upon and dissolve the coffee stains.

Video Instructions on how to remove coffee stains from a stainless steel thermos

  • Step 1 (1:15) — Add baking soda
  • Step 2 (1:37) — Pour in boiling water
  • Step 3 (1:55) — Let it sit
  • Step 4 (2:17) — Pour out mixture
  • Step 5 (2:58) — Scrub 

Frequently asked questions

How Does Baking Soda Remove Coffee Stains?

Baking soda, when formed into a paste, can be used to create gentle abrasions.

This paste can help to scrub away any coffee stains and coffee residue in your stainless steel thermos.

By adding boiling water and having it sit, the baking soda will dissolve the coffee stain from the stainless steel of the thermos.

Can I Use White Vinegar To Remove Coffee Stains?

White vinegar does an excellent job of removing coffee stains as its acidity will work to eat away and dissolve the acidity of the coffee stain.

It is particularly effective when used with baking soda to attack the build-up of coffee stains. 

You can use white vinegar to clean your stainless steel thermos and remove coffee stains.

The only concern is that you should not leave white vinegar to sit for too long in the stainless steel thermos as it can damage the 

How Often Should I Clean My Stainless Steel Thermos?

If you use your stainless steel thermos, it is essential to clean them one to two times a week.

If you are consistently drinking liquids, such as coffee or tea, out of it, you will want to do a full clean every time you use it. 

How Can I Avoid Coffee Stain Build Up In My Stainless Steel Thermos?

Regardless, the nature of coffee will cause coffee stains and build-up to occur no matter how diligent you are with cleaning it.

By washing regularly, you can cut down on the build-up.

Even if you are not at home or do not have access to cleaning supplies, you can rinse the thermos very well to mitigate the issue.

You will still need to do the occasional deep clean of the stainless steel thermos to remove coffee stains.

What Cleaning Products Should I Avoid Using In My Stainless Steel Thermos?

You will want to avoid bleach or similar cleaners.

These will cause the stainless steel thermos to stain.

Do not use scrub brushes that are too abrasive.

Using too abrasive scrub brushes on the stainless steel thermos will scrape the stainless steel on the inside.

Please do not put it in the dishwasher.

The chemicals in many dishwasher detergents will eat away at the stainless steel and erode it away.

Are Coffee Stains In My Stainless Steel Thermos Permanent?

No, If you have very dark or set-in coffee stains, that does not mean that they are permanent.

Not all hope is lost.

If you have dark coffee stains hanging around even after your regular cleaning, that does not mean that these will permanently stay in your thermos.

You may have some difficulty removing them, but you can remove the dark coffee stains.

If this is the case for your stainless steel thermos, you may need to repeat some of the steps above a couple of times to get out those dark and tough coffee stains. 

If this article was helpful, check out our similar article dedicated to teaching you how to get coffee stains out of plastic cups.