By June 15, 2010

Thermos Stainless King 16oz Coffee Travel Mug Review

We drink a lot of coffee at Gibberish. My coffee must be hot, ideally just right below the “omg this burned my mouth” hot. Coffee becomes bitter as it cools, so I want my Joe as hot as possible.

I had been using my caffeine molecule stainless steel mug from Think Geek before a visitor “borrowed” it and put spicy, flavored tea in it. This wrecked the mug, as the lid was tainted by the spice flavor despite repeated washings.

We started searching for a replacement, and Sedagive? returned with the Thermos King. Boy did it live up to its name.

Making hot coffee and keeping it that way is a three step process:

  1. Brew. Brew the coffee as close to 200°F as possible. We have a Bunn NHBX here at the house.
  2. Store. Store the brewed coffee in a glass-lined air pot, like my Thermos vacuum-insulated air pot. I also pre-heat the air pot by filling it with 200° F water made by my Upton electric tea kettle.
  3. Drink.

The last step seems the easiest, but this is where most of your coffee will go to waste. As I noted in my insulated mug shootout in 2007, coffee poured into a porcelain cup loses heat the fastest. In just ten minutes, a regular coffee mug will lose about thirty degrees of heat. That can make a serious difference in how your coffee tastes.

This may not be an issue if you drink coffee fairly rapidly. However, if you are on the go (or just demand super hot coffee) then you are going to need an insulated coffee / travel mug. In this space, the coffee travel mug made by Thermos is king.


The King employs two walls of stainless steel to help insulate your coffee from the frozen wastelands of your home. This isn’t particularly innovative. What I do find of interest is that the King is very heavy, which leads me to believe that it uses thicker layers of stainless steel. I thought it was a bit of a marketing gimmick at first.

The lid fits on very very tightly. The King lid is threaded, unlike less expensive “press-on” style lids. There is a rubber-ish gasket that compresses slightly when the lid is screwed down.

Lastly, there is an “open” and “close” lever on top of the lid. Some other travel mugs have this feature, and it’s mostly to keep heat from escaping, or colder air from getting in. The King donkey punches all of those lids, because the lever actually compresses a second gasket tightly against the bottom of the lid when “closed,” and releases the gasket when the lever is moved to “open.”

The King is supposed to be leak-proof, and so far it’s stood up to the claim. I set the latch to “close” and turned the mug upside-down. Over my face. No 200°F coffee in my face, so I believe the hype.


I don’t drink any cold beverages, so I only tested the King’s ability to keep things hot.

I heated up 16oz of water up to 200°F using my Upton Imports electric water kettle. I did not pre-heat the King with water. The King would have to warm up from room temperature (70°F) instead of 110°F from my tap. This is a departure from 2007 test, and I believe gave the older contestants an edge.

The King didn’t seem to care much. In fact, I saw so little variance at the thirty minute mark that I extended the challenge from 60 minutes to 285 minutes, or nearly five hours.

After thirty minutes the King only lost 10°F. The ThinkGeek mug, winner of the 2007 challenge, lost 30°F in the same amount of time.

Minutes elapsedInternal temperature (°F)

When I saw the thermometer read 150°F I was disappointed. That seemed pretty cool — until I took a sip. It was still warm, and still drinkable by my standards.


The King stainless steel travel mug by Thermos is top notch. Yes, it is more expensive than other mugs you may find at Target or Wal*Mart, but not substantially more expensive than vanity / boutique mugs found at places like Starbucks.

The King is so hefty it might even save you from a zombie in a pinch.

My only concern about the King is the longevity of the lid. Frankly, it may be too complicated, with two gaskets, a lever, and ratcheting mechanism. The lid goes on super tight, and perhaps the plastic threads on the lid may become worn with use. Only time will tell.

My King is fully stainless steel in color. There are apparently models in different colors, like a dark blue one. I couldn’t find the “natural” stainless steel in stock at Amazon, but Wal*Mart or Cabela’s may have the more traditional tone if you can’t abide blue.

Despite my worry about the lid, I still give the King Thermos my highest nod.

Strongly recommended.

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4 Comments on "Thermos Stainless King 16oz Coffee Travel Mug Review"

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  1. Christian says:

    Thank you for this review. I just happened to also be in the market for a new coffee mug.

  2. bc says:

    Curious as to how easy that lid is to clean. The fiancee drinks a lot of coffee, with lots of cream and sugar. The lid on this looks like it would be too complex to clean out the nooks and crannies easily.

  3. DrFaulken says:

    Hey bc,

    Sorry for the late reply but I wanted to try washing the lid myself first before I responded.

    The lid is easy to disassemble and wash by hand. I would be reluctant to put it through the washing machine because the heat may affect the gaskets.

    I will try to take some pictures with how to take the lid apart for cleaning.

  4. Will Kenderdine says:

    Perfect! : )
    …which is to say, “Thanks for the close-up pic of the lid!”
    I lost the instructions that came with the Thermos, then [carelessly] took it apart and soaked/cleaned it today, only to find I could not get the large gasket back onto the disk!
    …now I can see the gasket does NOT go on the disk, but rather on the lid.
    PS — perhaps my native language is Gibberish too since I understand your content quite well 😉

    Thanks again!
    Will Kenderdine