A thermos is a vacuum insulated container that keeps tea, coffee, or soup hot or cold for hours. It is important to clean a thermos frequently to maintain its insulation quality and avoid any bacteria growth inside. It can be cleaned with vinegar, hydrogen peroxide and other substances.

Steps of Cleaning a Thermos

1. With Vinegar
2. With Hydrogen Peroxide
3. By Using Dishwashing Soap and Water
4. By Storing Soda Water

1. With Vinegar

The first method that can be used for cleaning a thermos is with vinegar. A thermos that has hardened food inside it should be cleaned with vinegar. Use about three tablespoons of vinegar to ensure that the food inside the thermos is completely cleaned. Leave it for 30 minutes, then rinse with water and air dry. 

2. With Hydrogen Peroxide

For a thermos that requires a thorough cleaning, use two tablespoons of hydrogen peroxide. Leave it for 15 minutes, then rinse with water and air dry.

3. By Using Dishwashing Soap and Water

If the thermos is extremely dirty, you can use dishwashing soap and water to clean the inside of the thermos. After filling your thermos with water, you should drop about two tablespoons of dishwashing soap into it. This method will clean any hard-water deposits, but it will not work if the accessory is filled up with dried food particles.

4. By Storing Soda Water

If your thermos has dried-out food particles inside it, you should use soda water to clean it. This method cleans any dried-up food particles because soda water has a high carbon dioxide gas concentration. Just fill up your thermos with soda water and leave it overnight. The gas from the chemical will evolve and clear the unwanted particles from it. 

Tips on Cleaning a Thermos

– You can clean out your thermos with soap and water. Also, you can purchase a specialized cleaner from a store, but we cannot use alcohol to clear the spots in the thermos as it can react and damage the internal structure.

– Don’t forget about scrubbing around the lid while cleaning. This is where all those pesky bacteria are hiding. Using a toothbrush will help you get into all those nooks and crannies.

– After cleaning out old coffee stains with soap and water,  use a piece of cloth soaked with antibacterial soap to wipe down the insides of your thermos.

– Never put hot thermos in the dishwasher. The heat from the dishwasher could make the plastic warp or crack. You’ll also ruin your thermos if you put it in the freezer. The freezing temperature can cause internal parts to snap off, rendering your thermos useless.

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As a vacuum insulated container, a thermos helps to keep food and drinks warm or cold for hours. As such, it is important to clean the thermos from time to time to maintain its insulation quality. Apart from vinegar and dishwasher soap, hot soda can clean dried-up food particles inside it. Finally, you shouldn’t put your cleaned thermos in the freezer or dishwasher.

Frequently Asked Questions

Q. Why are scratches present inside my thermos?
A. While many people are not aware of the fact, the thermos is made of glass. As it’s always in contact with warm or hot liquids, it will agitate the particles within it. The scratches are not dangerous to your health because they are super tiny and quite deep.

Q. Why using dishwashing detergent damage my thermos?
A. Dishwashing detergent contains chemicals that go against the material used in the thermos. These ingredients may eat away at the plastic components regularly.

Q. What is the best way to clean my thermos properly?
A. Using dishwashing detergent and hot water is a good option for cleaning out your thermos, but we do not recommend this method for routine cleaning. It’s best to use vinegar and hydrogen peroxide with warm water every once in a while for deeper results.