Start a campfire in a safe location, away from trees and buildings. Use dry kindling to ensure your fire stays lit for the entire distillation process.
Place a glass tumbler in the middle of a saucepan, with the tumbler mouth at the top. Your tumbler should be thick glass that can withstand high temperatures. Thinner glass may crack and cause shards to break off. Your tumbler should not exceed the top of your saucepan.
Pour salt water into the saucepan carefully. Stop just below the mouth of your tumbler, taking extra care that you do not splash any salt water into the tumbler or on the mouth.
Place the cover of your saucepan over the tumbler, upside down. Most saucepan covers are domed, meaning your cover will be closer to the mouth of your tumbler.
Place your saucepan over your campfire using a metal rack or grill plate. Do not place directly into the fire. Grills and racks for boiling can be purchased at many sporting goods stores and provide excellent emergency use when kept on hand in your car or with your camping gear.
Boil your water for 30 minutes. As the water boils, the steam collects on your cover dome. The steam forms condensation that is free of salt and acids. The condensation then drips into your glass tumbler, leaving you with safe drinking water.
Allow your finished water to cool thoroughly, preventing burns on your delicate mouth tissues.