Water

Melt snow and ice for drinking water

You melt snow and ice for drinking water when liquid water is unavailable in freezing country. Start with a little liquid water, feed in clean snow or ice gradually, and maintain contact between the frozen material and the warming water. Dense snow and ice usually give you more water per potful than loose powder, but air content and water yield vary rather than following a fixed ratio. Boil the meltwater to kill pathogens, then protect it from contamination and refreezing.

Water 20 min practice Beginner Use this skill in snow-covered forests, mountains, and other freezing terrain where you can collect clean snow or accessible ice. Set up on a stable, sheltered outdoor surface, away from avalanche exposure, unstable ice, and overhead snow or ice.

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Topic summary

Key takeaways

You maintain a visible pool of liquid around the melting snow without an exposed, overheating pot base.
Each small addition melts steadily as you stir, without leaving a large dry mass above the water.
The entire batch reaches a rolling boil and stays there for the required time.
Your stored water stays liquid in a clean, securely sealed bottle without leaks or unsafe heat against your skin.
Avoid: Packing a dry pot full of powder creates insulating air pockets; start with liquid water and add small portions while stirring.
Avoid: Using dirty roadside snow or ice from suspect runoff risks contamination that boiling cannot fix; collect from a cleaner location instead.

Intended uses

Water skill (Beginner, ~20 min practice)
Requires: Cold-weather stove with a stable base, Metal cooking pot with a lid, Spoon or stirring utensil, Ignition source, Water bottles rated for the temperature of the water you will store

Climate suitability

Use this skill in snow-covered forests, mountains, and other freezing terrain where you can collect clean snow or accessible ice. Set up on a stable, sheltered outdoor surface, away from avalanche exposure, unstable ice, and overhead snow or ice.

Safety: Operate your stove outdoors, never in a tent or enclosed shelter, because carbon monoxide and fire can kill. Never eat snow directly for hydration: warming and melting it costs body heat and can worsen cold stress; keep hot pots and bottles away from bare skin.

Required tools

Cold-weather stove with a stable base
Metal cooking pot with a lid
Spoon or stirring utensil
Ignition source
Water bottles rated for the temperature of the water you will store

Required materials

Clean snow or ice collected away from tracks, waste, roads, and suspect runoff
A small reserve of liquid water
Fuel compatible with your stove
Dry insulating clothing or a bottle sleeve

Step-by-step

Start with a small amount of liquid water in the pot — even a couple of ounces — before adding snow.
Why: Starting with a small amount of liquid water spreads heat into the snow and helps prevent the pot from overheating while insulating snow sits above its base. Save a little meltwater to start each following batch.
Add snow gradually, stirring so the ice contacts water rather than dry pot metal.
Why: Adding snow gradually and stirring collapses air pockets and keeps frozen material in contact with warm water. This promotes steady melting instead of heating dry metal beneath a packed mass of snow.
Prefer ice or hard, dense snow over fresh powder — you get four times more water per volume.
Why: Ice and hard, dense snow contain less trapped air than fresh powder, so they generally yield more water per potful. The advantage varies with snow density; do not rely on a fixed fourfold yield.
Bring to a rolling boil for 1 minute (3 minutes above 6,500 ft) before drinking to kill pathogens from animal fecal contamination.
Why: Once all the snow and ice have melted, a rolling boil for 1 minute, or 3 minutes above 6,500 feet, kills waterborne pathogens, including those introduced by animal feces. Start timing only when the entire batch reaches a rolling boil; boiling does not remove fuel, salt, or chemical contamination.
Insulate the pot and store extra water in bottles kept close to your body so it doesn't refreeze.
Why: After extinguishing the stove and moving the pot off the burner, insulation slows heat loss and helps prevent refreezing. Transfer extra water into suitable bottles, check the seals, and carry them insulated near your body once they are cool enough to avoid burns.

Common mistakes

Packing a dry pot full of powder creates insulating air pockets; start with liquid water and add small portions while stirring.
Using dirty roadside snow or ice from suspect runoff risks contamination that boiling cannot fix; collect from a cleaner location instead.
Running high heat against an exposed pot base wastes fuel and can damage the pot; use controlled heat and keep liquid covering the base.
Stopping when the water merely melts leaves pathogens untreated; complete the rolling-boil treatment before drinking.
Pouring very hot water into an unsuitable bottle or letting a cooling batch sit uncovered risks damage or contamination; use a temperature-rated container and keep the water covered.

Troubleshooting

If you have no liquid starter, then gently melt a few small pieces of clean ice or a small portion of dense snow over low heat, moving them around until you have a shallow pool before adding more.
If the pot is hot but the snow is barely melting, then lower the heat, stir, and break up the snow so it contacts the liquid rather than bridging above the base.
If the stove weakens in the cold, then follow its cold-weather operating instructions and shelter it from wind without enclosing or overheating its fuel supply; never warm a fuel container with a flame.
If water begins freezing in storage, then move the sealed bottle into dry insulation near your body and melt any blockage before forcing the cap or drinking opening.

Field practice drill

In a safe outdoor spot, spend about 20 minutes melting a small batch. Begin with a little liquid water, add clean snow in portions, and stir while observing how each addition collapses into the water. Complete the altitude-appropriate rolling boil, extinguish the stove, and transfer the water safely into a suitable bottle. Insulate it and reserve some liquid for your next practice batch; do not shorten the boil to meet the practice time.

Indicators of success

You maintain a visible pool of liquid around the melting snow without an exposed, overheating pot base.
Each small addition melts steadily as you stir, without leaving a large dry mass above the water.
The entire batch reaches a rolling boil and stays there for the required time.
Your stored water stays liquid in a clean, securely sealed bottle without leaks or unsafe heat against your skin.

Related outdoor skills

Educational reference only. Wilderness conditions change fast — practice in low-stakes settings, take a certified wilderness first-aid course, and confirm regional regulations before you rely on any of these skills in the field.