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Bear Canister Bias

Thru-Fishing the JMT

5 x 8 Poncho as Shelter and Raingear

Esbit Stove Height vs Efficiency

Stoveweight vs Time Over 14 Days

Stoveweight vs Time Over 28 Days

Repairing Gear on the Trail

Washing Down Gear

Common Choices for Alcohol Fueled Stoves

Flying With Fuels

Resupply Options for Long Distance Hikers

MSR Pocket Rocket Tests

Pack Light Eat Right

Debunking Cookware Myths

For a Few Calories More: the Good, Bad, and Ugly of Trail Foods

Water Purification for Long Distance Hikers

MSR Pocket Rocket Tests

By Curt Peterson

MSR has long been a major player in the backpacking stove industry. I imagine there isn't a long-time backpacker out there who hasn't owned, used, or at least seen a Whisperlite stove. Unclogging jets, priming the burner, pumping the fuel bottle, and trying to control flare-ups just seem to be part of the backpacking rites of passage. MSR has offered a canister version of the Whisperlite for a long time, but in the past couple of years has put new energy into canister stoves with the production of the Superfly and the Pocket Rocket (3 oz., $34, hard case included). Because the Pocket Rocket is one of the lightest and most reasonably priced canister stove on Earth today, I chose it for summer backpacking and performed some at-home tests to find out how much fuel I would need for various trips.

Digital thermometer, food grade (+/- .1 *F) with integral stopwatch
Balance: Pelouze model K5 (marked accurate to +/- .5 oz)
Stansport 3 cup stainless steel cookpot with lid
3.5 ounce Coleman canister (70% Butane, 30% Propane)

2 cups of water at room temperature (60 degrees F) were used in each test. Two cups of water (16 ounces) at room temperature were used in each test. The fuel canister was weighed and mass recorded. The stove was attached to the canister and the pot with water was placed on the stove. The stove was lit, stopwatch started, then the stove was turned to full power. The digital thermometer was inserted into the pot. The stopwatch was stopped when the temperature was observed to reach 210 *F as reported by the thermometer. The pot was then removed from the stove and the canister was unscrewed from the stove burner. Any condensation was wiped form the fuel canister. The fuel canister was then weighed, and the ending canister weight was subtracted from the beginning canister weight to determine the mass of fuel consumed.

Trial Start Temp Max Temp Time to Max Temp Mass Fuel Used*
1 60 *F 210 *F 1 min 38 sec .3 oz
2 60 *F 210 *F 1 min 32sec .3 oz
3 60 *F 210 *F 1 min 55 sec .3 oz
4 60 *F 210 *F 1 min 45 sec .2 oz
5 60 *F 210 *F 1 min 48sec .2 oz
6 60 *F 210 *F 1 min 58 sec .2 oz
7 60 *F 210 *F 2 min 6 sec .2 oz
8 60 *F 210 *F 2 min 2 sec .2 oz
9 60 *F 210 *F 2 min 4 sec .2 oz
10 60 *F 210 *F 2 min 13sec .2 oz
11 60 *F 210 *F 2 min 36 sec .2 oz
12 60 *F 210 *F 3 min 10 sec .2 oz
13 60 *F 210 *F 4 min 35 sec .2 oz
14 60 *F 188 *F 5 min 28 sec .2 oz

* Ed Note: I suspect that the mass of fuel consumed per pint boiled was a number closer to .24 oz. The mass of fuel in the canister before testing was 3.5 oz, though the reported masses of fuel used only total 3.1 oz. By dividing the number of boils (and the last "partial" boil) by the mass of the fuel in the canister, .25 oz is obtained.


Conclusions:

This stove was much more impressive in the test than I had anticipated.

I was surprised to find out that as the burn times increased, the fuel consumption did not. That was a big bonus for me. I don't care if I have to wait an extra minute or so for hot water, but I don't want to use extra fuel during the time. This test proved that the stove isn't burning more fuel even though it's taking longer to do the job. I was also a bit surprised to find that the boil times didn't drop as fast as I expected. The boil time didn't double until the 12th test.

I was also surprised at the fuel economy in general. I never would have guessed that I would get almost 14 boils out of one of these mini canisters. That would easily last me a week on the trail. Pretty incredible for such a small setup. Canister weight aside, with only 0.2 to 0.3 ounces of fuel per boil, these canisters are more efficient than homemade alcohol stoves and even Esbit fuel tablets on a fuel-per-boil basis.

This testing used temperature as the deciding factor for heat because it's objective. However, it should be mentioned that the Pocket Rocket produced bubbles and steam as soon as 30 seconds into the boil. "Soft" boils, with large bubbles and obviously disturbed water surface (hotter than you'd want to drink!), occurred at around 1:15 with the stove for the first 10 or so boils. If your water is filtered, treated, or reliable, this is all you would need, potentially giving you up to 20 or so "soft boils" on one canister!

Opinions:

I've used the stove on blustery beaches along Olympic National Park's incredible coast and in warm, mild, windy, and rainy conditions in the Alpine Lakes and Goat Rocks Wilderness areas of Washington's Cascades. It has performed well in all these places - sometimes with a little help - and has definitely earned its place in my pack.

In temperatures above 45 degrees and little or no wind, you can expect the stove to perform similarly to the test below. On a recent trip with temperatures in the 50s and 60s, I got 12 full boils from a 3.5 oz canister. So far, at least, field conditions have not produced dramatically different results than at-home testing.

The greatest variable that does appear to affect this stove is wind. It can double and triple fuel consumption and boil times - an incredible performance drop. This can be mitigated, however, by choosing a spot that is well ventilated but sheltered from the wind.

The other variable that you can control is the temperature of the canister. As the temperature decreases, the pressure of the canister also decreases, leading to an increase in boil times. It will work, and probably won't be burning excess fuel, but will perform better if the canister is warmed in colder conditions. I usually do this by sticking it in my jacket against my body for a few minutes. This stove is best for boiling water fast for one or two people. It simmers perfectly, but quick and efficient boils are the Pocket Rocket's specialty.

Curt Peterson

 

AYCE says
Many thanks to Curt Peterson for his excellent objective research.

The performance of the MSR Pocket Rocket is comparible to the other lightweight canister stoves. However, its $35 retail price tag make it much more affordable than the other models. You can check out the specs on the Pocket Rocket in the Thru-Hiker Store.
 
Canister Weights
The mass of an empty 3.5 oz canister is about 2.7 oz, while the mass of a 7.8 oz canister is about 4.9 oz. Expect to get between 24 and 28 full boils out of the 7.8 oz canister.
 
Regarding the Results
I suspect that the actual amount of fuel consumed per pint boiled is a number closer to .24 oz. The total mass of fuel in the canister before testing was 3.5 oz. By dividing the total number of boils (and the last partial boil) by the total amount of fuel in the canister, I obtained .25 oz per boil.
 
Related Links
Here's an article called Debunking Cookware Myths that examines the heat transfer properties and efficiency of stainless steel, aluminum, and titanium cookware. It was written to debunk message board claims that titanium's heat transfer properties make it a poor choice for a hiking pot.


Interested in alcohol as a stove fuel? Here's an article that discusses all the different choices you have for appropriate stove fuels. Links to MSDS toxicity information for each fuel is provided as well.