I became enamored with cook pots that include heat exchange fins this year after watching a friend melting snow with one last winter with far less fuel than me. This led to my changing my cook pot for this winter from an 1.3 liter ultralight titanium pot to a comparatively giant MSR Reactor 2.5 liter cook pot.
Though designed exclusively for use with the cult classic MSR Reactor isobutane powered stove, I’ve adapted the 13.3 ounce Reactor 2.5 liter pot for use with a liquid fuel stove, the tried and true MSR Whisperlite. The problem with the Reactor Stove, and isobutane stoves in general, is that they are not effective in temperatures under 20 degrees Fahrenheit, rendering them effectively useless for New England winter backpacking trips where nighttime temperatures are often below zero. Liquid fuel powered stoves are the only option if you need to cook and melt drink water in such cold weather.
The MSR Reactor 2.5 pot is built very differently from other pots with heat exchange fins. Instead of having an external flux ring under the pot, the Reactor fins are enclosed inside a chamber that traps hot air against the sides of an inner pot, much like a double boiler stove-top system.
When coupled with a Reactor Stove, the Reactor pot and the stove are effectively windproof making for very efficient and fast boil ties. When coupled with an MSR Whisperlite, the pot and stove are less efficient and more prone to heat loss in the wind unless an exterior windscreen is used. Despite the resulting air gap between burner and pot, the Whisperlite quickly boils water in the Reactor 2.5 liter pot because the width of its gas jet is small enough to fit into the opening at the bottom of the Reactor Pot, enabling the heat it generates to be efficiently channeled up and into the pot’s interior heat retention chamber.
While I haven’t done any carefully timed measurements on boil time speeds (I leave that as an exercise for readers interested in doing that kind of testing), I can say that the combination of Whisperlite stove and Reactor pot boils water and melts snow much much faster and more efficiently, in terms of gas consumption, than my former stove and pot system.
Perhaps even more remarkable, is that the water in the pot will continue to boil even after it has been removed from the stove because the pot retains heat so well! Amazing.
High Carbon Monoxide Levels
On the flip side, the head product guy at MSR tells me that the cool surface of the pot can influence the combustion of fuel from a liquid gas stove and cause it to become incomplete. This translates to more carbon monoxide, which can be fatal if you cook indoors or inside a closed shelter like a tent. In such a case, having a less hot flame would be better for efficiency and reduce carbon monoxide output.
Despite providing much better much better fuel efficiency, MSR has concluded that all heat exchanger pots generate more carbon monoxide when used with an open flame stove. However, the level of CO is significantly reduced if the 2.5 L pot is used with a Reactor Stove, which is why they are so adamant about it. As a reminder, no stove should ever be used in an enclosed space. Not to worry, I always melt snow in the wide open to avoid setting my tent on fire, carbon monoxide poisoning, or worse.
But one of the features I like the most about the Reactor 2.5 L pot is its packability, especially since I use a 66 liter pack which is on the small side for winter. I’ve found that I can pack the Whisperlite stove, pump, and a plastic cup inside the pot along with a pair of fleece gloves, so that the pot itself takes up minimal extra space in my pack. In those terms, this pot is even more packable than the smaller winter pot I used to use.
There are many other features of the Reactor Pot I like including the clear top lid – complete with collender holes – and its detachable fold and lock handle, since I detest pots that require a separate pot gripper.
If there’s one downside to using such a large pot, it’s the need to carry a separate cup to eat and drink with since holding the full pot is too hot to handle and eat out of. But the convenience and extra efficiency of the MSR Reactor 2.5 L pot for winter camping seals the deal for me. Let’s face it, if you have to sit around in winter for hours to eat and melt snow, you might as well carry a few more ounces and bring the best pot.
Disclaimer: Philip Werner (SectionHiker.com) received a complementary MSR 2.5 liter Reactor Pot and Whisperlite Stove for this review
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