My Supercat will bring two cups of water to a rolling boil in 4-6 minutes depending on water temperature and wind. It will do this using between 0.75 and 1.0 oz of denatured ethanol depending, again, on water temperature and wind. In theory you might plan on getting two cups of water boiling in 4 minutes with 3/4 oz of fuel; in practice, I would plan on 2 cups in six minutes using a full oz. And, I would carry a bit of extra fuel.
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May I walk in beauty.