How to Clean a Thermos Flask

​We always want to keep most of our food and drinks at a constant temperature for various reasons and a thermos flask is the best companion for this. A thermos flask can be used to keep food and drinks hot or cold depending on how you want them.

Because it is a container that mostly handles things that we consume, we should always keep it clean. Lack of proper cleaning of the thermos flask you keep using may lead to a number of complications healthwise to the users. For instance, the food will start to develop an unpleasant smell that wasn’t there initially.

Cleaning of the thermos flask is necessary and highly recommended for obvious health reasons and you should learn all the proper ways to having a clean thermos flask to enjoy using at home or work.This article highlights the proper ways of cleaning your thermos flask at home. We know how difficult it is to clean a thermos flask mainly because it is made of very delicate material and we are in constant fear of breaking or damaging it. Bottom line is we have to clean the flasks no matter what or else a musky smell will be coming out whenever you open them or the interior will have build-up dirt that is not pleasing at all. The normal washing, that is, with a brush, soap and water will do for a day, but once in a while it is good to have the whole flask deep cleaned. The following steps will guide you through achieving the perfect clean of your thermos flask.

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The most common way of cleaning your thermo flask is using a dishwashing cloth, soap and water. This happens mostly when you are washing the utensils. First, you need to pour hot water in the flask followed by a liquid dishwashing soap. Allow the water to soak inside the flask for 10 minutes maximum.  After this, get a small dishwashing cloth and drop it in the flask.

Find wooden spoon to help you maneuver around the sides, the bottom and up to the neck of the flask as it removes the dirt. The hot water will have played a big role in removing most of the dirt so it is easier to have a clean thermos flask in a matter of minutes. When you are sure that all the dirt has come off, remove the dishcloth by tipping the flask upside down to coax the cloth by shaking and prodding the wooden spoon. Rinse the thermos with lots of water to ensure all the soap comes off.

How to Clean a Thermos Flask

​For a more stained thermos flask, you can use denture cleaning tablets, ice and salt or baking soda and vinegar to efficiently remove the stains. All you have to do is put the items in the thermos flask with considerable amount measurement. Let’s discuss the most common method of stain removal from a thermos flask.

​Baking Soda and Vinegar

How to Clean a Thermos Flask

Pour a cup full of distilled white vinegar into the flask then add baking soda into the vinegar and shake. This will cause a frothing reaction which will need you to have placed the flask in the sink. The mixture of baking powder and vinegar work by wearing down stains and killing germs in the process. Then, fill the flask with hot water and wait for a few minutes.

After that you just have to scrub lightly with a cloth and all the dirt will be gone. Rinse carefully and let it dry. These items are readily available in most kitchens to be used in times of need such as this.


​Cleaning a thermos flask thoroughly isn’t as hard, but the whole cleaning process should be treated delicately. Do not put the thermos flask in a dishwasher and you should not use solvents and bleach products since they might interfere with the inner workings of the thermos. Following such simple instructions can be very economical because you can have your thermos serving you for ages without feeling the need to get rid of it. The secret lies in how you clean. This way, any bad smell that might come up will be prevented.

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