Melting snow . Not so easy building a big fire and useing a canteen cup . This is why we use the 2 gallon pot and the modified hobo stove . We've got about a quart in 20 minutes or so just useing twigs broken by hand . One thing we forgot was our seed water .Better to start with water in the pot .So if you have a wiling assistant you can have a canteen ready while you set up your camp.