How to Clean Your Coffee Thermos

The cleaning steps will depend on how dirty your thermos has gotten. Start off with a regular wash using hot water and dish soap. Fill the thermos and then seal it with the lid.

Give your thermos a good shake to make sure the entire inside gets soapy and cleaned. If you need to repeat this a few times. A bottle brush will help you scrub the hard to reach places, so I recommend picking one up. 

Sometimes a really dirty thermos can get difficult to clean. The next trick you can use is mixing ¼ of a cup of baking soda inside and filling it with water. Let this sit overnight to break up the residue stuck to the sides. You can also use the old coffee carafe trick with rice and vinegar. 

Fill your thermos a third of the way with water, then mix in ¼ a cup of white vinegar and some dry rice. Seal your thermos and shake the mixture around. The rice will scrub the sides of the thermos while the vinegar loosens the residue. 

If all else fails, you can pull out one of the best thermos cleaners you can get, denture tablets. 

Fill the thermos with water and drop a tablet or two into it. Make sure you leave the lid off and let it sit until it stops fizzing. These tablets will break up and residue and mineral deposits that are on the sides and bottom of your thermos. I suggest leaving this for a few hours or even overnight. Finish it off with the bottle brush and dry it upside down. Voila, a perfectly clean thermos.