The Ultimate Insulated Growler Comparison

In early 2017 I set out to quantify which was the best-insulated growler on the market. The ubiquitous Stanley Thermos had slowly been squeezed out of the marketplace by newcomers to the market like KleanKanteen and Yeti. In fact, Yeti's 64floz Rambler took home the top prize for our first 64floz Growler Showdown.

Fast forward to 2018 and the market is exploding, with new insulated growlers popping up in stores every time I turn around. I decided it was time to revisit our original comparison. Taking note of feedback we received, I decided to make some tweaks to our testing procedure to ensure a repeatable process so that we could continually test and rank new growlers as they came onto the market.

Updated Testing Procedure

Unlike our 2017 test, where we placed the five growlers outside in near-freezing temperatures, this time we cleared out space in our home freezer. This provided an area where we could place two growlers in (reasonably) consistent -10°F conditions so that we can repeat these tests as new growlers come to market. As with our original analysis, we fill each growler with hot tap water (~140°F) and measure the initial temperature using an instant-read thermometer. We remove the growlers after six hours in the deep-freeze, shake them to ensure a homogenous water temperature, and record the water temperature using the same instant-read thermometer as before.

In addition to creating repeatable conditions for testing, we are also beefing up our testing by running each growler through three separate tests and utilizing the average temperature for the comparison. Our 2017 analysis revealed some incredible insights thanks to the use of FLIR thermal imaging, so we are employing the same technology in our ongoing evaluations. We hope to utilize this updated testing procedure to evaluate new growlers as they come to market, so be sure to check back often and see if the performance rankings have changed!

Testing Results

To start things off, we decided our updated tests needed to have a baseline to compare against. We wanted to see how well the insulation of these new growlers worked. After deciding on our testing procedure, we ran our firsts tests using Klean Kanteen's Classic 64floz bottle. As you will see in the data, below, our uninsulated bottle dropped an average temperature of 101.9°F. In one test, our final internal temperature was 32.7°F and ice had begun to form on the bottle wall.

Table 1: Performance Ranking

I believe OtterBox and KeanKanteen scored so well by tackling the same problem through similar designs. Both chose to minimize the opening size to maximize the surface area of water in contact with the insulated wall. OtterBox excelled in their design by choosing to reduce the neck and having the lid screw down into the body of the bottle to create a consistent insulative effect.

In this comparison, we are choosing to rank the growlers using two factors: average change in temperature and value. Our value ranking is really designed to "even the playing field" by factoring the growler's MSRP by multiplying it by the average change in temperature. This allows less-expensive growlers that may not perform as well be ranked higher than those that may be more expensive yet do not perform that much better.

Table 2: Value Ranking

It is when we rank the growlers by their Value that things really get interesting. I was surprised at how well the Ozark Trail, Walmart's value-brand, did against the competition, even beating out the winner of our 2017 competition. It is clear why the Ozark Trail is so much less expensive than the competition. The materials used just didn't seem to be of the same quality as the others. The lid experienced a noticeable amount of thermal expansion/contraction which resulted in it often being difficult to remove once it had been installed.

Digging Deep

The key takeaway from our 2017 comparison was the efficiency of a vacuum-insulated bottle is only as good as how/where the insulation is applied. I never expected there to be such a wide range of results from our 'test subjects.' Seeing the results got me thinking about what makes a top-performing insulated beer growler, or water bottle for that matter.

Like last time, we are able to leverage the images captured by the FLIR Systems C3 camera to evaluate the growler designs and hone in on the where the designs differ. You may have noticed in one of the images above that we placed black gaffers tape on the un-painted growlers. We did this to minimize any reflected heat that would show up in the FLIR images.  Although the external bottle temperatures were reasonably consistent, our thermal images revealed the weak-links, like last time, were the lids. Nothing is more evident of that than when comparing the Yeti Rambler, our 2017 winner, with its replacement, the new 64floz Yeti Jug. Although, and this is pure speculation on my part, the bottles are similarly constructed, but the YETI Jug loses its heat energy through the considerably larger lid.

Conclusion

So what does all of this mean for the average consumer? Well, unlike our 2017 comparison, I truly believe this year's takeaway should be that you do not always get what you pay for. Like 2017, our worst-performing growler was the most expensive, but the least costly growler actually scored in the top three. I believe if you are looking for the 64floz insulated growler with the best thermal efficiency, the OtterBox Elevation should be your choice. If you have budget constraints, then the Ozark Trail 64floz Vacuum-Insulated Bottle, winner of our Value Ranking, would be the best option.

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Author

Beau Johnston is an engineer, writer, and photographer who is dedicated to proving you can find a balance between work and life. He is the Co-Founder and Publisher of Living Overland, and when he isn't working, you can find him exploring National Parks, fly fishing, and camping with his wife (Krista) and their two dogs.

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