By July 19, 2011

Thermos King Stainless Steel Insulated Beverage Bottle Review

We drink a ton of coffee at the house. One of the best things I’ve ever purchased is the Thermos King stainless steel travel mug.

Sedagive’s work provides free coffee, but it’s terrible. The grounds are based on a robusta bean, and it becomes more or less disgusting depending on who brewed the pot. Plus who knows when the machine was last serviced, and if the coffee is being made at the right temperature.

At first we mitigated this by sending Sedagive? off with her own King travel mug. However, she’d finish up those delicious sixteen ounces and then have to drink the work coffee again. I started looking for a way to send her off with more home-brewed coffee, and the first place I looked was Thermos. Here’s my review of their King stainless steel insulated beverage bottle.
The 40-ounce Thermos King insulated bottle, with the companion travel mug in the background.

Construction and Specifications

The Thermos King insulated bottle follows the same design as the smaller travel mugs. It has two stainless steel walls for insulation. There are three versions of the King bottle: a small 16-ounce one, the 40-ounce model I reviewed, and a 40-ounce “heavy duty” model. If you are interested in the smaller 16-ounce model I’d suggest just buying another Thermos King mug; you will probably drink two travel mugs before either one of them loses too much heat. Look at the higher capacity 40-ounce bottles for longer-duration storage.

The lid is your classic screw off and drink out of, but unlike those classics the lid is made entirely of plastic. No metal here. I assume this is due to save manufacturing costs, but it makes me nervous about the long-term durability of an item designed to be toted around a lot. The lid is threaded, and screws down tightly onto the bottle’s cannister.
The stopper is also threaded, and is also made of plastic. You can pour liquid out without removing the stopper, something that may help keep hot beverages warmer for a longer period of time. You unscrew the stopper about a half turn, and the arrows indicate where the liquid will come out of. I’m not sure why they have two sides to the stopper; I think it would have been easier to dispense the liquid if they’d made the top totally round except for one slightly pointed side where the liquid came out.

Something troubled me about the stopper but it turned out not to be a big deal: it doesn’t screw totally flat onto the canister mouth.

It’s hard to see in photos, but not only does it not screw all the way down, it’s actually at an angle. I was afraid I’d threaded it wrong the first few times I tried. If your King thermos is like this don’t worry. All of the wet stuff inside stays where it’s supposed to 🙂 It’s stayed watertight after three weeks of use, with nary a leak.

The King has a folding plastic handle on one side. The handle is mounted by two metal rings. My biggest gripe with the handle is that it doesn’t fold flat easily, and typically is in “half-folded” mode. It also rattles when transported, which is annoying. More importantly, I’m concerned about the long-term durability of the handle because it doesn’t stay folded. I remember my dad’s all steel thermos coming loose in his truck and rolling around. For our usage this doesn’t bother me so much, but if you expect to be in a tougher environment it might give you reason for concern.


Thermos claims to keep hot liquids hot for about twelve hours. “Hot” is subjective, and for this test I consider coffee drinkably hot until about 150° F.

I ran two tests this time: one with a full bottle and one where I poured out 10-ounces of water every thirty minutes to see what the temperature drop would be as the bottle emptied with use. Both tests started with 195° F water and an unheated Thermos king bottle at a room temperature of 70°F.

Full bottle test

DurationTemperature (°F)
1 hour195°
2 hours195°
2 hours195°
3 hours190°
4 hours185°
5 hours180°
6 hours160°
7 hours160°
8 hours160°
9 hours150°

If you open your Thermos King bottle within 8 hours your hot beverage will be hot enough for you to enjoy it.

Progressive test

DurationTemperature (°F)
1 hour195°
30 minutes190°
30 minutes175°
30 minutes165°

I drained the Thermos King insulated bottle after two and a half hours. This taught me more about my own coffee consumption rate than it did the performance of the Thermos King. 🙂


If you drink out of the Thermos King travel mug for an hour or two and don’t open the Thermos King bottle until you’re done, you might be able to coast through an 8-hour work day with hot coffee all day long. If you drink coffee more slowly you will definitely be fine.

For less than $25, the Thermos King stainless steel insulated travel bottle is a good value and companion to your mug.

Strongly recommended

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