I was recently given a 2.5 pint capacity Kelly Kettle. If you’ve never heard of a Kelly Kettle, it’s a device made from aluminum used for quickly boiling water using a small fire that burns in the open center of the kettle that is surrounded by a hollow jacket that holds water. Yesterday a friend stopped by who recently purchased a 1/2 gallon capacity Thermette, which is a similar type of device from New Zealand made of copper. We decided to do a side by side comparison to see if there were any significant differences between the two.

The two devices are very similar and built with the same design principles. They both sit on a small stand that serves as a firebox and firepan. After grabbing some twigs and pinecones we lit them at about the same time. They both reached a full boil quickly and within less than a minute of one another, after roughly 8 minutes. We could have gotten them to boil faster if we had focused on doing so, but we were chatting and adding sticks slowly. You feed the fire in both of them by adding material through the chimney hole on top. The big difference between the two that we found was the capacity; the Thermette holds more water, and with a smaller opening on top (which is on the opposite side in these photos so you can’t see it) loses less when the water starts to boil and bubble.

The Thermette comes with a separate cooking ring that sits on top of the chimney so that you can cook on it, a neat addition that makes it that much more versatile. There is a similar device available for the Kelly Kettle, but you have to order it from their website. You can see in the photo below the cooking ring in action with a percolator sitting on top. You can also use the cooking ring on top of the firebox without the Thermette, giving you a small twig stove.

Both of these are simple and functional, but since they take up roughly the same amount of space in a pack but the Thermette heats more water, we both figured it was the more desirable of the two.

There is also a 2.5 gallon capacity Thermette advertised on the web that is hard to locate from within their site.