1.0 KiB
Boiling Water to Make It Safe
Boiling is the most reliable way to kill bacteria, viruses, and protozoa in questionable water. It does not remove chemical contaminants, heavy metals, or salt.
How long to boil
Bring the water to a rolling boil for 1 minute at normal elevations. At elevations above 6,500 feet (2,000 meters), boil for 3 minutes — water boils at a lower temperature as altitude increases, so it needs longer at the boil to reach the same level of pathogen kill.
Let the water cool naturally. Do not add ice to speed cooling; ice made from untreated water re-contaminates the batch.
Improving the taste
Boiled water tastes flat because boiling drives off dissolved air. Pour it back and forth between two clean containers a few times to re-aerate it, or add a small pinch of salt per quart.
Before you boil
If the water is cloudy, let it settle and pour it through a clean cloth or coffee filter first. Boiling cloudy water still works, but sediment shields some organisms and makes the result unpleasant to drink.