Yes, 1/4 cup=4 tablespoons. That is a LOT of fuel to heat two cups of water. Most of us expect 2 cups to boil on 2 tablespoons or less of fuel. If you are simply having a hot beverage and rehydrating pre-cooked food, getting the water to about simmering should be enough. Most pathogens that bother humans die at 180 F. This probably won't kill spores like cryptosporidium or giardia, though.

You can save a LOT of fuel getting foods that require actual cooking up to boiling for a minute or until your fuel runs out, then insulating your pot. Something like beans that might need a long cooking time may require this "coasting" method combined with a few repeat boil episodes. Many of us carry an insulating sleeve made from windshield reflectors or water heater insulation (Reflectix)or simply wrap our pots with a hat or fleece jacket.

CamperMom