Backpacking Stove Fuel: How Many Canisters, and Why It Fades in the Cold

It’s 23 °F on the plateau, the sun hasn’t cleared the ridge yet, and your pot has been sitting for long minutes over a flame that looks like a pilot light. The canister isn’t empty, though: it’s just cold, like your fingers. How much fuel should you carry, and why does your stove fade right when you need it most? Manufacturers’ spec sheets answer the first question, as long as you read their test conditions. The second comes down to a little kitchen physics.

This guide builds on our guide to your first backcountry camping trip, where a stove takes the place of a campfire. The math for one night’s fuel, meal by meal, is in our guide to backpacking food; here, we look at what makes that number move: the stove, wind, cold, the fuel blend, and the canister itself, then flying, recycling, and safety.

How much fuel it takes to boil 1 liter of water

For each of its stoves, MSR publishes how much water 1 oz (28 g) of fuel brings to a boil: 1.7 to 2.8 liters for its canister stoves, depending on the model and the pot [1]. Per liter, that works out to roughly 0.35 to 0.56 oz (10 to 16 g) of fuel. The PocketRocket 2, a small stove that screws onto its canister, runs at about 0.49 oz (14 g) per liter, the number in our food guide. The 1.7-liter Reactor, an integrated systemA burner and pot designed together; the pot has a heat exchanger under its base, fins that capture the heat from the flames., gets down to 0.35 oz (10 g).

Those are rarely backcountry conditions, and MSR says so itself [1]. Burn time matters too: one 8 oz (227 g) canister lasts about an hour on a PocketRocket 2 [2], and the instructions for Campingaz’s Bivouac stove list a rate of 6.7 oz (189 g) of gas per hour [3]. Every minute of flame costs fuel: that’s why couscous or a freeze-dried meal, which rehydrate off the heat, go easier on the canister than pasta, as our food guide explains.

If your water comes from a creek, the boiling time that kills germs adds to the total: our guide to backcountry water has the details.

Wind and cold: what the spec sheet doesn’t count

Wind is the number one fuel thief. On an open-flame burner like the PocketRocket’s, a 5 mph (8 km/h) wind can triple fuel use for the same cooking time, according to MSR, which adds that low temperatures, melting snow, and wind can call for three to four times your baseline amount [1]. Icy water from a mountain stream also stretches boiling time. The double our food guide suggests for an ordinary night covers small surprises; in wind or snow, MSR is talking triple or quadruple.

Your first instinct, wrapping a windscreen around the stove, depends on the model. MSR recommends one on a remote-canister stoveA canister set apart from the burner and connected to it by a fuel line, as on the WindPro II., wrapped about half an inch (1.3 cm) from the pot, to send heat up its sides [1]. On a stove that screws onto its canister, it’s the opposite: the PocketRocket 2’s instructions say never to use any kind of windscreen [5]. Look for natural shelter instead, a boulder or a dip in the ground, keeping the stove at least 8 inches (20 cm) from any wall or combustible object, as the instructions for Campingaz’s Bivouac require [3], and put a lid on the pot: MSR lists that among its fuel-saving habits [1].

Butane, isobutane, propane: what’s in the canister

A stove canister holds liquefied petroleum gasPropane, butane, or isobutane: gases in open air, kept liquid under pressure inside the canister.: liquid at the bottom, gas on top. The stove burns only the gas, and that gas only forms if the liquid boils. So everything hinges on its boiling pointThe temperature at which a liquid starts to boil, here at the pressure of the surrounding air.: the lower it is, the more pressure the canister holds in the cold, MSR explains. Propane boils so low that at -44 °F (-42 °C), poured into a cup, it would sit there like water without vaporizing [6].

Hence the blends. MSR’s IsoPro is 80% isobutane and 20% propane [6], and Primus lists around 20% propane and 80% isobutane in both its Power Gas and its Winter Gas [10]. Pure propane would need a much heavier canister to handle its pressure [6], and some stoves can’t take it, like Soto’s WindMaster [11]. At the other end of the shelf, bargain canisters often hold straight butane, according to MSR, which admits it’s fine if you only camp in warm weather and for short periods [6]. The blend is printed on every canister: it’s the first line to read at the store.

Why your stove fades below freezing

Cold attacks on two fronts. First, it lowers the pressure in the canister and slows the evaporation of the liquid: the flame weakens, or goes out, even though there’s fuel left, Primus explains, adding that the effect gets worse once the canister is no longer full [10]. Then the canister chills itself as it runs, because a liquid that evaporates pulls heat away, like sweat on your skin; with a fuel already short on pressure, that cooling finishes off the stove’s performance, according to MSR [6].

Manufacturers’ benchmarks come with conditions attached. MSR says upright canister stoves usually work down to about 20 °F (-6.5 °C), and struggle more and more below that [1]; the PocketRocket 2’s instructions say not to operate or store it below 0 °F (-18 °C) [5]. Some stoves have a pressure regulatorA part that keeps the flow of fuel to the burner steady as the canister’s pressure drops.: Soto’s catalog pitches it as the fix for the pressure drop of chilled fuel [12], and MSR builds one into its WindBurner, which runs at full output as long as the canister stays above 32 °F (0 °C) [2]. A regulator can’t create pressure, though: in freezing temperatures, the canister’s pressure can drop below what even the regulator can maintain, MSR warns [13].

Enlarge diagram

Winter canisters work on what’s inside. Primus lines its Winter Gas canister with absorbent paper that increases the surface area the liquid evaporates from. In its test, two full canisters spent 48 hours in a freezer, then burned in a cold room at -4 °F (-20 °C) on two identical stoves: its own delivered about 9% more power after 60 minutes, and 15% after 120 minutes [10]. That’s a manufacturer testing its own product, so read it as such: the gain is real, but the blend matters first.

What helps in the cold, safely

Nothing flashy, but it all adds up:

1. Pick your canister by its blend: isobutane and propane rather than straight butane [6].
2. Keep it warm before you cook, in a jacket pocket or your sleeping bag, as MSR suggests [13].
3. Set it in a container of water that isn’t freezing: as long as the water stays liquid, it keeps the canister warm enough for the stove to keep going [13]. MSR also suggests setting it in warm water before you light the stove [1], never hot: a canister should never go above 122 °F (50 °C) [14].
4. Put a lid on the pot, and don’t keep lifting it: you can hear when it boils [1].
5. Only flip the canister upside down on a stove built for it, a remote-canister model like the WindPro II, which then runs in liquid mode [1]; on the WindBurner, MSR forbids it, warning of dangerous flare-ups [2].
6. For real winter camping, MSR points to its integrated systems or a liquid-fuel stove [1].

How to tell what’s left in a canister

A canister won’t tell you what’s left in it; a kitchen scale will. It takes two subtractions: the listed full weight minus the listed fuel gives the empty weight, and what the scale reads minus that empty weight gives the fuel left. Our food guide applies this to the small 3.9 oz (110 g) IsoPro; here are all three sizes, from MSR’s product page [15].

Example: an 8 oz (227 g) IsoPro that weighs 8.8 oz (250 g) still holds about 3.7 oz (106 g) of fuel. No scale? MSR prints a float gaugeA scale printed on the canister: set in still water, it floats higher or lower depending on the fuel left, and you read the waterline off the scale. on its 4 oz and 8 oz canisters [15, 6]. The label helps too: the cartridge below lists 190 g (6.7 oz) of butane and a gross weight of 280 g (9.9 oz), so it weighs about 90 g (3.2 oz) empty. Finally, before you throw a canister away, the instructions for Campingaz’s Bivouac say to shake it and make sure you can’t hear any liquid [3].

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Threaded valve, Campingaz valve, pierceable cartridge

The European standard EN 417, in its 2012 version, covers non-refillable metal cartridges of 50 to 1,000 ml, with or without a valve, for contents whose pressure doesn’t exceed 13.2 bar at 122 °F (50 °C) [16]. The connections, however, aren’t all the same, and they aren’t interchangeable.

• The threaded valveA valve with a screw thread that the stove screws onto., the most common for backpacking. MSR says the majority of canisters worldwide use this thread, and that a stove designed for it generally works with well-made canisters from other brands, though it can’t guarantee it [17, 6]. The PocketRocket 2’s instructions, for their part, only allow MSR canisters certified to EN 417 [5].
• The Campingaz valve on CV 270 Plus, CV 300 Plus, and CV 470 Plus cartridges, mostly a European system: Cotswold Outdoor, a British outdoor retailer, describes the CV 470 Plus as available in more than 50 countries across Europe [18]. It screws on about a sixth of a turn, until it clicks, and comes off even before the cartridge is empty. It refits on Campingaz appliances from the same range, designed for these cartridges only, and the Bivouac stove’s instructions warn that using other gas containers can be dangerous [3].
• The pierceable cartridgeA valveless cartridge that the appliance punctures as it’s attached., like the 190 g cartridge pictured above. Since the 2012 version of the standard, it must have an internal leakage limiter [16].

Enlarge photo

Two last warnings from MSR. Never use a refilled canister: you can’t verify what’s in it, or whether there’s enough room for the liquid fuel to expand [17]. And no forced adapting: the PocketRocket 2’s instructions warn that trying to fit other types of gas containers may be hazardous [5]. If you borrow a stove, our gear checklist suggests checking that the canister fits it before you leave.

Carrying, storing, and recycling

In the car and at home

Fuel fears heat far more than cold. Campingaz’s safety data sheet says not to expose cartridges to more than 122 °F (50 °C), not to leave them in a vehicle in the sun, and not to store them below ground level, in a cellar or basement: if there’s a leak, the gas, which is heavier than air, collects in low spots [14]. The Bivouac’s instructions add a cool, dry, well-ventilated place, out of children’s reach [3]. Put the cap back on after use: Soto insists on it, to keep the valve clean [11].

Where campfires are banned

In some national parks, the stove is the only flame you’re allowed. Rocky Mountain National Park prohibits campfires in its wilderness and tells backpackers to use portable stoves only [19]; Mount Rainier bans fires on its trails and in its backcountry, but allows white gas, isobutane cartridge, and alcohol stoves, not stoves that burn twigs, sticks, or cones [20]. Rules vary from park to park, so check before you go. France works the same way in places: in the core of Écrins National Park, a 2026 order allows only portable gas stoves and bans any other combustion device [21]. Our park-by-park guide to French national parks and our guide to campfire rules in France, where some prefectural orders ban even stoves in times of fire danger, have the details.

The empty canister

Where an empty canister goes depends on your county. In King County, Washington, small gas canisters such as camping canisters can go in the garbage once they’re empty, and empty or partly full tanks of 8 gallons or less are accepted at hazardous waste facilities [24]. Los Angeles County Public Works, on the other hand, answers that empty small propane canisters like those for camp stoves can’t go in the trash: propane tanks count as household hazardous waste, to drop off at a collection event or a City of Los Angeles SAFE Center [25]. Check your county’s rules before you toss one. And never puncture or burn a canister, even an empty one, Campingaz’s safety data sheet warns [14].

Carbon monoxide: the stove stays outside

A gas stove can produce carbon monoxideA toxic gas, invisible and odorless, produced when fuel burns.. The PocketRocket 2’s instructions put it up front: the stove is “for outdoor use only,” never to be used in an enclosed space such as a camper, a tent, a car, or a home [5]; those for the DragonFly, another of the brand’s stoves, add the vestibuleThe area covered by the rainfly in front of the door, outside the tent body. to the list [26]. Campingaz also rules out its Bivouac in a tent, a shelter, or any small enclosed space, and while sleeping [3]. The CDC says never to use a portable gas camp stove indoors, and counts, each year, more than 400 Americans killed by unintentional carbon monoxide poisoning not linked to fires, more than 100,000 emergency department visits, and more than 14,000 hospitalizations [27]. In France, about 3,000 people are accidentally poisoned each year, all appliances combined, and around a hundred die [28].

The same logic applies in a camper van: our guide to camper vans in winter covers heating, CO detectors, and ventilation.

The smart move before every trip: weigh the canister, read its blend, and check the forecast low for dawn, not the afternoon high. The rest happens outside, always outside.

Worth watching

Adventure Alan tests popular backpacking stoves outdoors in cold wind and explains how he compared them: a hands-on complement to the manufacturers’ figures above.

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Guillaume Hoarau

Camping, backpacking, bushcraft and hiking

Guillaume Hoarau writes for Outfarer about camping, backpacking, bushcraft, and hiking. A survival-skills buff and a collector of vintage field manuals, he loves clear explanations, lists that actually help and other people’s stories, which he tells well.

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