If you melt snow in winter for drinking water, you still need to purify it before you can drink it. The easiest to do this is to let it boil for 1 minute if you’re below 6,562 feet (2,000 meters) of elevation or 3 minutes if you’re above 6,562 feet (2,000 meters). Boiling is the surest method to kill disease-causing organisms, including viruses, bacteria, and parasites. These are the CDC (Center for Disease Control) recommendations and I’ve always found them reliable.
Freshly melted snow is generally considered to be safe to drink without further treatment, however it should not be assumed that because water is frozen that it is safe to drink. Exercise the same caution for melted Ice as you would for standing water, and if in doubt boil the water for 10 minutes.
Alternative Water Filtration/Purification Methods in Winter
Water filters are unreliable in winter because they can freeze, which will usually ruin the filter. They’re also difficult to keep from freezing when not in use if you’re camping outdoors in the cold. While we recommend carrying extra fuel for boiling your water, you can also use the following two methods to purify snowmelt or bring them as a backup in case your stove fails. No kidding: stoves can fail in winter. I’ve had it happen multiple times, always with canister fuel stoves.
If you can’t boil snowmelt, perhaps because you’re low on fuel, you can use chlorine dioxide tablets, like Katadyn Micropur to purify liquid water. You can add a chlorine dioxide tablet (usually 1 per liter) to a water bottle as long as the water is in liquid form. Katadyn Micropur destroys viruses and bacteria in 15 min., Giardia in 30 min and Cryptosporidium in 4 hrs. If you’re not worried about “Crypto”, then adding a tablet to lukewarm water will purify it pretty quickly.
Ultraviolet light is another viable way to purify snowmelt, using a Steripen. Ultraviolet light doesn’t add any taste to the water and is even faster than using chlorine dioxide tablets. The only real issue with a Steripen is that you need to keep the batteries warm enough to use. Some people hang a Steripen around their neck on a string, under their baselayers to keep their batteries operational.
How to Boil Snow for Drinking Water | Outside
FAQ
Is it OK to melt snow for drinking water?
How do you make snow water drinkable?
How do you purify melted snow?
Can you save snow for water?
Can you drink water from melting snow?
A subtle nuance with obtaining drinking water from melting snow, is the smoke from the fire can affect the taste of the water. Other successful snow melting methods call for the snow to be suspended above the fire line, which usually resulting in an undesirable taste, due to the smoke penetration.
Is melted snow safe to drink?
Ultimately, it is essential to consider all options and potential risks when it comes to obtaining clean drinking water in difficult situations. Melted snow can generally be safe for drinking, assuming it is not from a polluted source and has been properly boiled, treated, or filtered.
Can you drink melted snow if you boiled it?
Filtering melted snow is a recommended step to ensure water purity, even if you’ve boiled it. Even though snow is generally clean, this extra measure removes potential impurities and enhances the safety of the water for consumption. Is Snow Pure Enough to Drink? According to the CDC, snow should be boiled before drinking.
How do you keep snow from melting water?
Opt for snow that lacks any discernible smell. Before collecting snow, scrape off the top layer, as it may have encountered airborne pollutants. This extra step helps ensure the purity of the snow you’re using for melting water. Shovel or a scoop. A clean container. Stainless steel pot. Heat source (stove or fire). filtration system.