I have owned a Jetboil bivvy stove since 2005, used it primarily on expedition climbs at altitude where weight is an important factor, and mainly for melting snow and boiling water for drinks and de-hi/ instant noodle meals. I recently replaced my old one with a new Jetboil Flash and took this climbing in Afghanistan in July.
The cooker consists of an 800g cup with an insulated neoprene ‘cozy,’ a burner with piezo lighter, a plastic lid, a plastic base cover which doubles as a cup and an orange fuel canister tripod. Attached to the bottom of the cup and enclosed by some thin metal is the ‘flux ring’ ie. a wavy bit of metal that serves as a heat exchanger to improve the efficiency of the stove. When packed up it measures 18.5cm tall and 11cm in diameter and weighs approximately 420gms.
Putting the cooker together is easy and it is nice and compact, although I didn’t find it as sturdy as my old version. There is a small black button that triggers the piezo igniter, and when pushed, it produces a solid “click” and a small spark is visible over the burner. However, this wasn’t that reliable about 5000m and I generally resorted to a match.
The flame output is controlled by a small rectangular section of wire. When not in use, the wire folds back underneath the burner body and stows away nicely. It’s a wee bit fiddly and occasionally it would fall off; but all in all it works fine.
The neoprene ‘cozy’ that surrounds the metal cup has a webbing handle and hand loop on one side. The handle can feel a bit insecure if you aren’t used to it- just a matter of persevering without scalding yourself. Another tip is to make sure the hand loop is positioned away from the spout on the lid, otherwise it can be hard to grasp it if the water is boiling and spitting out the top. Ditto the wire control for the flame control- make sure this also is on the opposite side to the spout.
The cooker has a ‘color changing heat indicator’ and according to Jetboil, the three lines that constitute the Jetboil logo on the ‘cozy’ turn orange when the contents of the stove are hot. I never really used this and just relied on seeing steam coming out the top, but I shall use it in the future- might save a few scalded fingers.
The cup attaches to the burner assembly by a ‘click and turn’ method and although this worked well, I found it insecure compared to my old Jetboil stove; a little bit wobbly! New for this version of the Jetboil is a tripod for the gas cylinder and this is a great innovation, as in the past I have carried a piece of closed cell foam to keep the cylinder off the snow.
The tripod, burner, and custom Jetboil fuel canister (which you don’t have to buy- any screw top canister will do) stow easily inside the cup. According to the manufacturer, the Jetboil Flash boils 2 cups, or half a litre.
Although this is not a cooker to take on a tramping trip, for anyone who climbs hard and needs to reduce weight, is looking to exist on ‘just add water ‘ meals, or needs to melt snow in a hurry, you wont go wrong with the Jetboil Flash. An alpinist’s must have.