Ultralight Backpacking Fuels, Alcohol and Esbit – Insights from the field

Alcohol stove fuel and Esbit tablets really can be the workhorses of ultralight cooking. The usual canister vs. alcohol vs. Esbit review doesn’t really capture practical or best practices approaches to these two fuels.  Here are my tips on how I make these fuels work well for me in my backcountry kitchen to boil water, to rehydrate a freeze dried meal or bake a chocolate cake. Even in the rain.

It’s not just the fuel, but really the whole system that counts.  That includes fuel, burner, pot support, windscreen, simmer control, stove lighting and extinguishing, burn time, outdoor temperature sensitivity, refueling ease, fuel storage and some factor for operating fussiness.  Add to this weight and cost considerations for both the basic system and for fuel and you will be well on your way to making choices.  Some popular stove products do a good job on addressing most issues, think Jet-Boil.  See how I do better.

Fuel Weight

On a winter day trip, I can carry 4 fl. oz. of stove alcohol in a plastic bottle, 4 Esbit tablets in a small Ziploc bag or a 1/2 empty small isobutane canister.  Coupled with a good stove/pot/windscreen system each of these quantities will boil 2 quarts of water, and I will  have canister gas left, even it is cold.  Since this amount of fuel gives me a typical day of backpack cooking with some reserve, fuel weight no longer becomes a big deal.  For a 5 day trip, I might pack 14 fl. oz. of alcohol, 14 Esbits tablets or 2 small gas canisters.  Weights for these quantities, including storage, are 12.6,  7.4 and 15 oz. respectively.  The biggest weight differential for this extended trip – Esbit over isobutane canisters – is only about 7-1/2 oz., something, but not compelling. Still alcohol and Esbit are lighter.

In the field, I always know how much fuel I have left by counting tablets or checking fl. oz. level marks on the side of my used Coke bottle alcohol containers.  If I think I will need a little more or less fuel for the trip, it is easy to adjust 1/2 oz. by 1/2 oz.  To reduce the risk of alcohol leaking or spilling from a single bottle, I can split my reserve into two bottles at less than an oz. weight penalty.  Esbit tablets have a fishy smell, so I carry them in a small, 7″ x 7″, odor proof OpSak bag.  I often take some of both fuels to give me options and backup for cooking.

Windscreen/Pot Support

Nothing messes with a backpacking stove’s performance like wind and nobody likes spilled noodles. Integrated windscreen/pot support solutions to ultralight cooking are best practices.  My choice are the cone style products offered by Trail Designs.  Flat Cat Gear’s Bobcat cooking system is another good option.  Both use the windscreen to fully enclose the stove’s burner, channel the hot combustion products up around the pot body to an exit just below the pot rim, and finally stably support the pot.  Adding a reflective bottom liner provides a sheltered, reflective cavity for the heat transfer from the hot gases to the pot.  This bottom liner sheet can be easily made from heavy duty aluminum foil, if one doesn’t come with the windscreen. The windscreen interior volume gives the burner and fuel a relatively constant temperature space for operation, sheltered from the wind.  Both firms offer versions that will pack inside a pot for compact storage.  The windscreens sit close to the ground with wide bases and are much less likely to get tipped over in operation – no spilled noodles.  They are all light, typically weighing only a few ounces.

Fuel Burner (stove)

Getting stove alcohol or Esbit tablets to burn steadily, at a controlled rate is harder than you might think.  A good burner is an essential component to the overall system and needs to be matched to the pot/windscreen combination to get the right distance from the flame to the pot and adequate volume for combustion to complete.  The vent openings in the windscreen must match the burn rate to provide the right amount of air for operation.

Of all the alcohol stove variants I have seen, bought or built, my favorite is the 12-10 stove by Trail Designs.  It has it all.  It is easy to fill, with a central, open pot.  Combustion air comes from vents in the exterior of the double wall burner.  The flame emerges from the center of the stove, directly below the pot allowing the maximum amount of gas flow around the pot base for good heat transfer. The stove base serves as a priming pan for quick ignition.  An optional adjustable air flow control simmer attachment gives low output operation.

My favorite Esbit tablet burner is the Ti-epicurean stove from Flat Cat Gear.  It consists of a simple rectangular pan and a titanium ring with scallops cut around one edge.  The ring has a handle that allows it to be turned over so that the scallops are up or down.  A single Esbit tablet fits inside the ring.  With the scallops down, air flow is directed to the base of the burning tablet, producing a hot central flame.  With the scallops up, the flat bottom of the ring seals to the pan, limiting air flow and producing a low output, simmer operation for extended burn times.

With a cone windscreen and the 12-10 stove, 1 fl. oz. of alcohol will will burn for 17 minutes at full output and 48 on simmer.  The figures for the Epicurean stove are 10 and 30 minutes for a single Esbit tablet.  I use the simmer operation for dry baking.  For both stoves it reduces the heat output to about one third of full fire.

The stoves work really well and weigh about 1/2 oz. each.  The flame height is about the same so I can use either one in any windscreen/pot combination.

Stove starting and stopping

Just turn the valve and hit the piezo igniter button.  When done, turn the valve to off.  Wish it were that simple!

Alcohol is the easiest of ultralight fuels to deal with.  With the 12-10 stove, squirt or pour a little extra fuel in the priming pan.  Hold your lighter close until you see/sense that something happened.  Alcohol flames are not very visible, but if things get hot, you succeeded.  The alcohol in the priming pan will burn, heat up the main stove body, ignite vapor from the central pot and away you go.  Put the windscreen in place, centered on the stove and drop the pot in place.

Conventionally alcohol stoves are used as “one shot” devices.  Put in the amount of fuel you need and let it burn until out.  That wastes of fuel, especially if you are not sure of how much you need.  Better practice is to put out the flame when you are done.  Sometimes you can do this with a big puff.  I use a snuffer made from the bottom of a beer can.  My 12-10 stove snuffer uses a 24 oz. Modelo Especial can.  Drop it over the lit stove and it’s out.

If you are going to be cooking again shortly, leave the snuffer in place.  When you are ready, fill the primer pan, add more alcohol to the stove, if desired and light.  If you are finished, any extra, unburned alcohol in the stove pot can be sucked up with a spout attachment installed on the pop fuel storage bottle.  My spout came from Packafeather.

Esbit tablets are more difficult to light.  I usually hold one corner of the tablet over my lighter flame.  When I think the tablet has caught enough, I set it down in the burner pan.  Any wind makes this tough.  I have a friend that lights a windproof match and sets it on top of the tablet.  The match flares wildly and the tablet ignites.  I carry some of these matches just in case.  With the tablet lit, just place the burner ring over it with the holes up or down as desired.  Drop the windscreen and pot in place and you’re done.

Again, Esbit tablets can be extinguished by blowing really hard.  I use a another snuffer.  My Esbit snuffer is smaller, made from the bottom of an 8 oz. Coke can with a slot cut in the side for the Epicurean burner handle.  The tablet will smoke for a while, but it goes out.  The unburned portion can be relit or saved in a used tablet pouch for later.  Not as convenient as alcohol, but it works.

Titanium Pot

I think a titanium pot is essential to a well prepared backcountry kitchen.  It is light and tough.  Overheating can’t damage or destroy it, and it is reasonably non-stick, compared with aluminum.  When dry baking, a titanium pot will discolor to shades of brown to blue.  A thin oxide layer causes this.  It does no harm, and can be polished off.  Jewelry makers use torches to carefully produce these colors on their products.  I like pots that are more compact to give a larger bottom surface for heat transfer.  Pick one that suits your meal needs.  Because titanium has a lower heat conductivity than aluminum, you may see boiling start at the upper edge of the water rather than at the bottom.  However there is no significant difference in performance.

Useful Accessories

I pack a couple of other items to round out my typical kitchen.  These include a GSI silicone pot grabber at 1/3 oz.  Esbit tablets sometimes leave a brown residue on the bottom of pots.  I carry a small, 1 g., square of kitchen scouring pad that easily cleans my titanium pots with a little warm water.  I also made a 1 oz. pot cozy out of reflective attic insulation.  I use it to finish cooking and rehydrating meals.  It also serves as a holder for eating out of the pot while keeping the food warm.  I line the bottom of the cozy with a 0.6 oz. circle cut from a silicone baking sheet.  This protects the bubble wrap material from the hot pot and keeps the pot from sticking if there is some Esbit residue on the bottom.

Putting it all together

Let’s say I am packing for a three day, two night, solo trip.  I am going to cook mostly with alcohol, but will take my Esbit stove and some tablets as an alternate or backup.  I am taking a smaller, 780 mL Titanium Snow Peak pot, together with a split style cone windscreen that packs into the pot.  Eight fl. oz. of fuel packs in an 8 oz. pop bottle with my Packafeather spout installed.  I put 3 tablets in my OpSak bag, which also holds the Flat Cat Epicurean stove base and my pot cleaning scrubby.  The pot, windscreen, aluminum foil bottom shield, Epicurean stove, alcohol 12-10 stove, snuffers and pot grabber all go into the cozy for carrying.  The alcohol and Esbit bag are carried in an outside pack pocket.  My total weight for this list is only 19.8 oz.

For this weight, I get a complete, stable, rugged, redundant cooking system.  It is quiet, simmers and is temperature and wind resistant.  I can dry bake without damaging the pot, which is also easy to clean.  I can carry just the amount of fuel I need and easily keep track of how much is left. The system and stoves can also be adjusted to different size pots for heavier or lighter cooking needs.  For the small added weight of an extra windscreen and pot, I can have two stoves going at once – stew and biscuits, not bad for ultralight.

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