How To Properly Clean a Push Button Thermos Lid

Thermos travel mugs are a lifesaver for those who like their coffee on the go. Using your thermos daily can result in wear and tear, but it can also get dirty really quickly. The thermos lid is a fantastic breeding ground for mold and bacteria, so you need to wash the lid properly. 

To properly clean the push button Thermos lid, you will need to gently take apart the lid of the thermos and soak all the parts in warm soapy water for 10 minutes. For stubborn dirt, use one teaspoon of baking soda and ½ cup of white vinegar. 

Over time the gasket and lid can grow mold, harmful bacteria, and your lid will even begin to smell, which is not something you want anywhere near your mouth. 

Learning how to clean a push button thermos lid will go a long way in preventing harmful bacteria being consumed. 

Step 1: Disassemble The Lid 

Disassembling the lid of your thermos is probably the most tricky part of this cleaning process, but by following these instructions, the process should be stress-free. 

• First, unscrew the top section by turning in an anti-clockwise direction. It should come apart fairly easily
• Next, remove the rubber gasket from the bottom as this is a common place that collects mold.

I go into detail on exactly how to disassemble the lid in my video down below:

Step 2: Soak The Lid in Vinegar

First give the parts of the lid a rinse to remove any leftover coffee, tea or other drinks that may be on there.

Before getting in there with a good scrub, I recommend soaking the parts of the lid in one part vinegar and one part water for 30-60 minutes or even overnight.

Vinegar is a natural mold killer so if you have any mold in the lid it should kill it effectively.

Soaking the lid will also help stubborn dirt and mold to break up.

Step 3: Scrub The Lid 

Those hard-to-reach places in your thermos lid, like underneath and around the button, are where you need to be cleaning the most.

Here are some cleaning tools you can use to reach those spots:

• Pipe cleaner 
• Bottle or spout brush 
• Cotton swabs 
• Clean toothbrush

I personally like to use this bottle brush cleaning set from Amazon as it comes with a long handle bottle brush which is great for cleaning the inside of my thermos really well but also comes with smaller brushes for those gaskets and hard to reach areas. Great for cleaning other Thermos or bottle lids too.

To tackle those really stubborn spots, you can use a mixture of baking soda and distilled white vinegar. Mix 1 teaspoon of baking soda and ½ cup of distilled white vinegar and scrub the lid until it is clean. 

The baking soda works as an abrasive to more thoroughly wash the parts of your lid and the chemical reaction between the vinegar and baking soda also helps to clean things really thoroughly.

Be sure not to use any harsh chlorine-based cleaners, and always rinse off the baking soda and vinegar mixture thoroughly before you use the thermos.

However, if the mold is still hanging on, you may want to mix about 1 teaspoon of bleach with hot water and let it soak for five minutes before scrubbing again. Do not wash the outside of the thermos or any metal parts with bleach.  

Step 4: Rinse and Reassemble 

When you are happy with how clean your thermos is, you can rinse it and then leave it to dry. Once completely dry begin to resemble the lid. To do this, simply work backward from how you removed the lid. 

• Place the gasket back onto the lid with the smaller section of the gasket facing down
• Screw back on the top piece of the lid
• Check the push mechanism to make sure the lid still works
• Screw it back onto your thermos 

Now your thermos is clean and ready to be used again, just remember to rinse the thermos out after each use, especially if you used milk in the thermos. 

To learn more about using milk in a thermos, check out my article on coffee with milk in a thermos.  

Replacement lids 

If the idea of taking apart your thermos lid just to clean it sounds like too much work, I suggest buying a replacement lid for your thermos. Many of the thermos brands will sell replacement lids off their website. 

Or you can buy the replacement links from Amazon.

How Do I Stop My Thermos From Leaking?

A leaky thermos is super annoying, especially if you’ve left it in your lunch bag with your other food. A leaking thermos usually means that the button mechanism is broken or perhaps the rubber gasket is broken. 

To stop the thermos from leaking you will need to either fix the broken push button by realigning the spring in the lid or just buy a replacement lid. Check out this helpful YouTube video on how to fix the push button lid. 

If you do not want to disassemble and reassemble the lid on your thermos, I suggest buying a replacement lid. 

Learn more about a broken thermos vacuum by reading my article on why your Stanley Thermos isn’t keeping food hot anymore. 

What are The Best Ways to Clean a Thermos Lid? 

One of my personal favorite ways to clean my own Thermos lid is to make a baking soda paste out of baking soda and water. 

I apply this paste with a cloth and let it sit. After it sat on the lid for a couple of minutes I scrubbed the lid using a bottle brush. 

Learn more about cleaning a Stanley thermos properly with my helpful guide.