Until now, there hasn’t been a simple, accurate way to quickly check how much fuel is left in a partially used camp-stove fuel canister. When I wanted to know how much life remained in one of mine, I’d have to shake it, drop it in water to see if it’d float, or weigh it. But those methods resulted in little more than educated guesses, and so I’ve slowly built up quite the store of half-empty canisters. Rather than be stuck with one that might run out on me in the middle of a backpacking trip, I would buy a fresh full one each time I set out—though I haven’t brought myself to throw the old canisters out, knowing I could still get cooking power out of them at some point. And so they’ve accumulated (there are about eight that I can find), strewn among the tents and skis in my garage like spent Coors Light cans in a frat house.
That’s why I’m happy that Jetboil has come out with the JetGauge Canister Weight Scale ($15). The hockey-puck-size hang scale is remarkably easy to use. A cap screws to the top of your Jetboil fuel canister, and a single button turns the scale on and allows you to toggle through the different sizes (100 grams, 230 grams, and 450 grams). Once that’s done, pick the JetGauge up so that the canister is hanging, and it tells you, as a percentage, how much fuel you have left. Based on that percentage, you’ll have a good idea of how many times you can bring water to a boil with the remaining fuel. For example, on a 100-gram canister, 100 percent equals 24 boils, 75 percent equals 18 boils, and so on. Factors like altitude and extreme cold could skew those numbers, but it’s a much better start than shaking a canister and guessing at the number of uses you have left in it.
I have no excuse not to use those partially empty canisters now that I have the JetGauge, so it could very well cure me of my fuel-hoarding compulsion. Take, for example, the canister that was sitting near the red goal of my foosball table. I thought it didn’t have more than a couple of boils left based on a shake test. Then I whipped out my JetGauge and it read 25 percent, enough for a couple of days of regular use. Instead of squirreling that canister behind the laundry detergent or the vintage Bible my grandma gave me, I think I’ll take it with me camping this weekend.