Once you invest in a Stanley Thermos, you expect it to keep your beverages piping hot or ice cold for extended periods. Over time, you may notice an unpleasant odor or taste developing inside the thermos.

This is due to the accumulation of bacteria and other contaminants, which can compromise the effectiveness of the thermos. With the right cleaning techniques, you can ensure that your Stanley Thermos remains in pristine condition for years.

How to Clean Stanley Thermos? (step-by-step)

Tools and Materials Needed

Before you start cleaning your Stanley Thermos, you will need to gather These few tools and materials.

  • Hot Water
  • Dishwashing Soap
  • White Vinegar
  • Baking Soda
  • Bottle Brush
  • Microfiber Cloth

Step 1: Empty the Thermos and Rinse it Out

Empty out any leftover liquid and rinse it out thoroughly with hot water. Remove the lid and pour out any remaining liquid from the thermos.

Step 2: Add Dishwashing Soap and Hot Water

Next, add a few drops of dishwashing soap to the thermos, along with hot water. Use enough water to fill the thermos to the brim.

Step 3: Shake and Swirl the Thermos

Shake the thermos vigorously to create a soapy solution. Then, swirl the thermos around, ensuring that the soapy water touches all parts of the interior of the thermos.

You can also use a bottle brush to scrub any hard-to-reach areas inside the thermos.

Step 4: Rinse the Thermos

Now rinse it out with hot water. Remove all traces of soap and suds from the thermos.

Step 5: Add White Vinegar and Hot Water

If you still notice any still stubborn stains or an unpleasant odor, add a mixture of white vinegar and hot water to the thermos.

You can use a 1:1 ratio of white vinegar and water for this mixture. Now swirl the thermos around.

Step 6: Let the Mixture Sit

Allow the white vinegar and hot water mixture to sit in the thermos for at least 30 minutes. This will penetrate any remaining stains or odors.

Step 7: Rinse the Thermos Again

After the vinegar and hot water mixture has had time to work its magic, empty it out of the thermos and rinse it thoroughly with hot water once again.

Step 8: Add Baking Soda and Hot Water

If there are still any lingering odors or stains, create a paste of baking soda and hot water. Apply the paste to the interior of the thermos.

Step 9: Scrub the Thermos

Again use a bottle brush to scrub the interior of the thermos. Let the paste sit in the thermos for a few minutes before rinsing it out thoroughly with hot water.

Step 10: Dry the Thermos

Finally, dry the thermos thoroughly with a microfiber cloth. Make sure to dry all parts of the thermos, including the lid and any crevices or hard-to-reach areas.


Keeping your Stanley Thermos clean and well-maintained is essential for its longevity and performance.

By following my step-by-step guide outlined in this article, you can ensure that your thermos remains in pristine condition, free from any odors, stains, or bacteria.