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MSR Reactor Review

This one-trick pony is slowly being rendered obselete by easier-to-use stoves
MSR Reactor
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Price:  $240 List | $219.95 at Backcountry
Compare prices at 3 resellers
Pros:  Fast boil time, storm-proof, easy to use
Cons:  Heavy, pot does not attach to stove, does not simmer, expensive
Manufacturer:   MSR
By Ian McEleney & Jessica Haist  ⋅  Apr 29, 2020
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58
OVERALL
SCORE


RANKED
#12 of 17
  • Fuel Efficiency - 25% 7
  • Weight - 25% 6
  • Simmering Ability - 20% 2
  • Ease Of Use - 20% 6
  • Boil Time - 10% 9

Our Verdict

Once cream of the crop for boiling water in harsh climates, the MSR Reactor was crafted to provide quality performance in all conditions, for one to three people. Unfortunately, it functions poorly on low, lacking the ability to simmer. The MSR WindBurner may be rendering it obsolete as it has taken the best features of the Reactor and some from the Jetboil stoves and rolled them up into one. The Reactor is a great tool for boiling water very fast and will stand up to all kinds of weather — alpine climbing, mountaineering, and backcountry ski trips are all good applications. However, it lacks some of the conveniences of the other integrated canister stoves.

Compare to Similar Products

Our Analysis and Test Results

The Reactor is a leader in its class in boil time and foul-weather performance. In other categories, it's lacking. If you are a backpacker who likes to cook the occasional meal, this is not the stove for you. We also had some concerns with a malfunction while testing this stove.

Performance Comparison


Glen in an open bivy in the High Sierra  getting his morning brew ready on the MSR Reactor.
Glen in an open bivy in the High Sierra, getting his morning brew ready on the MSR Reactor.

Issues with the Reactor


We experienced a malfunction while testing the Reactor. While we were doing our boil tests, the burner would not light properly, and the flame seemed to sit on top of the metal grate and remain a blue wispy flame, not the red hot one we are used to. After contacting customer service at MSR, it was determined that this was indeed a malfunction. It should have been jumping down to the metallic foam burner itself instead of sitting on top. One potential issue is that we were testing in a garage with very little air movement. MSR told us they have experienced this problem while doing lab tests indoors with no air movement, so they advised us to cook outdoors.

They also told us it is preferable to light the Reactor with a strike ignitor type lighter so that the sparks land directly on the metallic foam burner. If you use a lighter (or a match), make sure to light the stove at the edge above the MSR logo on either side of the burner. There is a small opening in the top dome where the screen has been stretched to help the flame reach the burner surface. We have read other reviews online of those who have experienced this problem. That being said, our testers have used other Reactor models and have never had problems before.

MSR did give us a quick fix to this particular problem that you can use if this happens to you while you're in the backcountry. If you see a blue flame after lighting the stove, you can briefly place a finger or thumb just in front of the air intakes on either side of the control valve. This essentially acts as a choke (like on a carburetor) to reduce the air intake and richen the fuel mixture. It will make the flame jump down to the metal foam and turn red very quickly. Be careful doing this if the stove is warm as the solid ring around the top of the stove could be very hot. We tried this on our malfunctioning burner, and it worked!

Our MSR Reactor malfunctioned  and the wispy blue flame shown here would not "jump down" to the metallic foam burner below. We contacted MSR's customer service to troubleshoot this problem.
Our MSR Reactor malfunctioned, and the wispy blue flame shown here would not "jump down" to the metallic foam burner below. We contacted MSR's customer service to troubleshoot this problem.

A Thermal Trip Mechanism shuts this stove down if it overheats to prevent a nasty canister explosion. This is not a common occurrence, but once it's deployed, the stove is simply rendered inoperable — leaving you without a functioning stove.

Fuel Efficiency


The Reactor is in the middle of the pack for fuel efficiency when there's no wind. It was the most fuel hogging integrated canister stove but still outperformed the small canister and liquid fuel stoves. In our 2 - 4 mph wind test, however, this stove really shone. In front of the fan, it was tied for the most fuel-efficient, while every other stove (of any type) used more fuel to bring water to a rolling boil.

After it was lit, but before we had time to put a pot on, this burner would occasionally blow out. This was the only time we lost the flame. You can usually prevent this by shielding the burner with a pot or a windscreen, but it's cumbersome and kind of takes three hands. Fuel spent in the lighting process definitely detracts from efficiency.

THE MSR Reactor heat exchanger. This is a more durable design than the JetBoil Flux Ring heat exchanger.
THE MSR Reactor heat exchanger. This is a more durable design than the JetBoil Flux Ring heat exchanger.

Weight


For a stove that we like to bring for fast and light alpine missions, the Reactor is not as lightweight as we would prefer. With a 1L pot, it weighs in at 14.5 ounces — about average for an integrated canister stove. That said, if you consider the integrated canister stove as a pot, stove, and bowl all in one, it may save some weight compared to a liquid fuel stove.

Simmering Ability


As with all the integrated canister stoves we tested, the Reactor is not as versatile as we would like. While it may be a champion at boiling water, it will not slowly reduce your pasta sauce, fry up an omelet, or cook rice. In fact, this stove simply does not simmer, and it is relatively poor at running on low at all. During our attempts to simmer delicate cuisine, we extinguished the burner dozens of times. If simmering is something you often do during your cooking adventures in the backcountry, consider a different stove, it's not what the Reactor is meant to do.

Getting ready to go test the Windburner and the Reactor back to back in cold condiions - don't forget the Ramen!
Getting ready to go test the Windburner and the Reactor back to back in cold condiions - don't forget the Ramen!

Ease Of Use


This stove is shorter and squatter than some of its competition, making it more stable. Even when filled completely and held at full extension for pouring, the handle hinge on the Reactor showed no sign of flex. To our pleasant surprise, the handle also makes for an excellent bottle opener. Additionally, the pouring spout built into the pot meant that we spilled less than every other integrated canister stove, something that's really nice when you're making coffee in your sleeping bag.

As mentioned previously, unlike its competition, the Reactor does not attach to the burner. Although it is easier to remove the pot from the heat source when it is about to boil over, in general, we prefer the burners that couple securely with the pot and think this is a big weakness for this stove.

Trish McGuire using the MSR Reactor and the Melitta Ready Set Joe to brew coffee while camping at Charlotte Dome.
Trish McGuire using the MSR Reactor and the Melitta Ready Set Joe to brew coffee while camping at Charlotte Dome.

We were unpleasantly surprised to see that the burner on the Reactor does not fit neatly into the 1L pot. It fits awkwardly, and most of the times that our testers were able to pack the burner and a 4-ounce fuel can inside, it wouldn't stay together. This is in spite of the fact that the burner has a frustratingly small control knob.

Unlike many liquid fuel stoves, which roar like jet engines and turn dinner into a shouting match, the Reactor is wholly tranquil. Based on our observations, it is possibly the quietest stove on the market today. The only problem with this is that we occasionally had to lift the pot up or take off our gloves and put our hands by the vents to make sure it was actually on and not just wasting gas.

Users should be aware that the Reactor pots do not have cozies, and become very hot during use. It's easy, if you're not careful, to melt synthetic material, say, the sleeve of a puffy jacket.

The Reactor and the Jannu at 11 800ft.
The Reactor and the Jannu at 11,800ft.

Boil Time


This is where the Reactor really shines; its red hot burner boils water fast. In our no-wind tests at 7980 feet, the Reactor brought 1 liter of water to a rolling boil in 4 minutes and 3 seconds. While it was malfunctioning and we only managed to get a blue flame out of it, it still worked eventually, boiling a half liter in 3 minutes and 54 seconds. In our 2 - 4 mph wind test, this stove continued to dominate, boiling its liter in just a bit longer than when it was calm.

The burner on the Reactor has several unique features that make it faster than all the rest:
(1) It is the widest of all stoves tested (roughly 3.5 inches in diameter).
(2) It's surrounded by perforated metal, which acts as a windscreen and captures air for the burner.

(3) Unlike most stoves that only use convective heat, the Reactor's burner incorporates metallic foam that also dispatches radiant heat.

The MSR Reactor in the alpine with the morning Alpenglow  where it belongs.
The MSR Reactor in the alpine with the morning Alpenglow, where it belongs.

Value


The Reactor is expensive, more than any other integrated canister stove. If you're after something bigger, you have the option of purchasing the 1.7-liter or 2.5-liter pots, a great option, but the WindBurner is a much better value and has better features if your stove absolutely must be able to operate in the wind.

Conclusion


The MSR Reactor is near and dear to our hearts, and at one time was the only windproof stove. Now other stoves on the market are close enough in some ways and so much better in others that it's hard to justify bringing this one out for its one trick: boiling water in the wind.

Hanging out in the high country with the iconic Reactor.
Hanging out in the high country with the iconic Reactor.

Ian McEleney & Jessica Haist