P recently built a few alcohol stoves from empty Bud Light aluminum bottles. The plans are easy to find on the internet--and luckily we have a friend who likes Bud Light. P would have hated to pour the stuff out---but it really isn't his kind of beer!
The plans are pretty simple, and P managed to make the stoves using really basic hand tools. A small saw, a drill, some sandpaper, and fifteen minutes later you have a pretty decent alcohol stove.
So how does it work? It takes a few seconds, maybe twenty, for the alcohol to heat up and start to vaporize through the gas jets. Then it burns just like the burner on our gas stove at full blast for as long as there is fuel. And then it slowly dies down and goes out. This thing puts out lots of heat while there is fuel--and at room temperature, it boiled a quart of water in about three minutes or so, with about one ounce of fuel. Pretty efficient!
But there are some down sides as well. You can't control the heat--it's either ON, or it's off. That isn't the best solution for M, who is a chef and likes to be able to moderate the heat as needed. The burner pattern is pretty big--bigger than many small backpacking pots. (the perfect combination would be one of these stoves with a cookpot made of a larger Fosters beer can...but most of the flame from this stove would go right past the bottom of that pot. That's not efficient at all.)
And once it's on, it has to burn out. If you try to blow it out, it will just burn hotter...and maybe blow flaming alcohol all over the forest. ahem. (Yeah--there are ways that you can smother the burner once it's lit...but if the goal here is a light stove, taking extra parts complicates that.)
These also seem to use more fuel than our MSR Pocket Rocket. With the Rocket, we use about one ounce of fuel per day to boil water twice a day--once at dinner, and once for breakfast. But these alcohol stoves use about twice that amount. Then again, the PR gas canister weighs more that a plastic bottle filled with alcohol...weight probably works out about the same.
In the end, everyone will have to make their own decisions about these stoves. We've give a few to friends, for them to play with. And we've kept a couple for ourselves, too.
But M doesn't think we'll be using them for backpacking. She likes her Pocket Rocket.