Quick Answer
Snow is safe for consumption when it has fallen from a significant height, been contaminated with less than 100 parts per million of pollutants, and melted slowly to allow for the elimination of bacteria and other pathogens.
Snow Formation Conditions
Snow that has formed from clean, cold air and has fallen from a height of at least 1,000 feet (305 meters) or more is considered safe to melt and consume. This is because the intense cold at higher elevations kills bacteria and other microorganisms, reducing the risk of waterborne pathogens. Additionally, snow formed from clean air tends to have fewer pollutants and other contaminants.
Melting Snow Techniques
To safely melt snow for consumption, it’s essential to melt it slowly over a low heat source, such as a candle or a low-wattage stove. This allows for the elimination of bacteria and other pathogens, making the water safe to drink. A good rule of thumb is to melt the snow at a temperature of 160°F (71°C) or higher for at least 30 minutes to kill all bacteria and pathogens.
Testing for Safety
If you’re unsure about the safety of the snow, test it by melting a small sample and observing its clarity. If the water is clear, free of odors, and has a neutral pH, it’s likely safe to consume. However, if the water is cloudy, smells bad, or has a pH level outside the normal range (6.5-8.5), it’s best to err on the side of caution and find alternative sources of water.
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