Thermos Stainless King 40 Ounce Beverage Bottle Review

Insulated Thermos Stainless King 40 Ounce Beverage Bottle Review PhotoProbably the most famous and classic name in all of beverage bottles, Thermos is a company with a long and successful history which we’ve written about in the past. With over a hundred years of experience under their belts, there is no doubt that their modern products like the Thermos Stainless King have quite the pedigree behind them – but how do they stack up against their new-fangled rivals?

The Thermos Stainless King packs quite a few features rather uncommon to water bottles, giving the Thermos its own distinctive appeal. While suitable to hold just about anything you want to put it in, the Thermos has always been more suggestive to us as a vessel for hot liquids than cold, a suggestion enhanced by some of the Stainless King’s features. But Thermos’s patented insulation advertises its ability to keep liquids hot or cold for up to 24 hours. Since the Stainless King’s lid doubles as an insulated serving cup, this Thermos is a perfect selection for sharing some hot beverages when the weather gets chilly.


Insulation is Everything: The Thermos Stainless King vs Hydro Flask and Other Modern Water Bottles

Genuine Thermos Brand Insulated Water Bottles Photo

Thermos Stainless King 40 Ounce Insulated Beverage Bottle From BehindWith a 40 ounce capacity and a price tag of around $27 the Thermos Stainless King is much cheaper than a comparably sized Hydro Flask, which can run over $40. In addition to being cheaper, the Thermos also offers some more substantial insulating power when it comes to hot liquids: where the Hydro Flask advertises its capacity to keep things hot for 6 hours or cold for 24, the Thermos boasts 24-hour insulation no matter the temperature.

In our testing, the claim to the Thermos insulating for up to 24 hours is somewhat tenuous. No doubt liquids were still warm after 24 hours, but they had certainly lost a lot of heat. Regardless, the Thermos’s insulating power is no joke and head-to-head offers much better insulation for warm liquids than a comparably sized Hydro Flask.

The bottle itself is well insulated enough that you can’t feel much heat transfer when holding the bottle, regardless of how hot or cold its contents are. However some areas on the upper parts of the Thermos feel a little less insulated (probably primarily where the lid screws onto the neck of the bottle) and will sometimes be a bit warm to the touch if the liquid in the bottle is particularly hot.

Helpful Features

Pouring coffee from the Thermos Stainless KingThe Thermos Stainless King features a carrying handle, which is somewhat unusual for these types of bottles actually very convenient. One minor complaint is it can sometimes be rather noisy if the bottle is being rattled around and the metal handle is knocking against the bottle. The handle is well-made and well-secured to the bottle, however I would assume it to inevitably be the least durable part of the bottle and probably the first thing that might break off.

Actually – if the handle failed, it’d probably be the only thing to break off. The Stainless King is made from high quality 18/8 food grade stainless steel and while you might manage to dent it or scratch it up, it would take a serious amount of force to put this Thermos out of commission.


The lid on the Stainless King is a simple screw-on top which secures very well, providing enough leak-proofing to let you toss about the (properly secured) Stainless King with no worries of spilling its contents. The lid is made from the same 18/8 food grade stainless steel as the rest of the bottle, making this an all-stainless-steel storage solution; perfect for anyone who wants to avoid any plastic touching their beverages. But best of all, the lid doubles as a small insulated serving cup. This makes the Thermos Stainless King an ideal way to transport your coffee, coco, or ice water for later and have plenty for the entire day without struggling with drinking from a large bulky bottle.

Once you remove the lid, the mouth of the Stainless King includes a pouring mechanism which has to be opened (pictured above,) providing an additional layer of leak-proofing and also making it easy to dispense beverages from the Stainless King without worrying about spilling it everywhere.

A Bottle with a Purpose

Thermos Stainless King ASsembly Diagram for Lid and Pour SpoutThe Thermos Stainless King is lightweight and portable enough to be something you use as an everyday water bottle. Yet the nature of its lid which doubles as a cup and additional pour spout makes it less something you drink from directly and more of a storage vessel for liquids to be poured from it. This, once again, suggests to us that the Thermos is something more ideally suited towards hot liquids than cold ones. And while you can see from the assembly diagram (pictured right) that it is possible to remove the pour spout and drink directly from the Stainless King, Thermos specifically warns us not to do this on the Amazon listing so it is clear this is not how they intended the bottle to be used.

That said, the Thermos certainly lends itself more to something you might use everyday to store your coffee or tea. But as an everyday general carry bottle, its probably not your top pick (check out our Best Water Bottles of 2016 if that is more of what you’re looking for.) But on a picnic, a camping or hiking trip, or anywhere you want to share a warm beverage, the Thermos Stainless King is the first bottle I would grab.


Review Summary

Man Drinking From Thermos Stainless King OutdoorsThere is no doubt that the Thermos Stainless King is a pretty awesome product. It provides brilliant insulation, quality construction and manufacturing, and a very practical and useful product at an impressively affordable price. While its features lend it more towards holding hot liquids, its insulation works exceptionally well on either end of the spectrum and the bottle is an excellent container for whatever you choose to put into it. Though it is something we save more for a pot of hot coffee for the office or on the hiking trail, you could even use the Thermos Stainless King as your everyday water bottle if you wanted to.

Probably out main complaint with the Thermos Stainless King is a minor one: it is rather difficult to clean. With the narrow-mouthed opening and the large size of the bottle, you’ll definitely want to invest in a water bottle cleaning brush to make sure you can get the inside of your Thermos Stainless King nice and clean after use.

We award the Thermos Stainless King 5/5 stars.

Learn More about the Thermos Stainless King

To read other customers reviews, get more information on details and specifics, check current prices, or purchase your own Thermos Stainless King, be sure to visit the Amazon listing.


Superb Insulation
Quality Construction
Trusted Brand


Bulky & Heavy

  • Editor Rating
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  • Thermos Stainless King
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  • Last modified: March 12, 2017

The latest and greatest iteration of the classic brand-name Thermos design.

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