Does Boiling Water Purify It: Myths and Safe Practices

Whether you are brushing your teeth, cleaning utensils, or looking for a fresh drink, water is one of the most vital substances in the world. The average human body is made up of 50 – 65% water, so it should come as no surprise that we need water to survive. If lost with limited resources and no back-up hydration plan, we must ponder the primary question any outdoor enthusiast asks while preparing for a journey into the wilderness: does boiling water purify it?

Although you can survive weeks without food, an adult human is supposed to drink at least 64 ounces of water daily. Expert survivalists estimate a person lost in the wild can survive from 32 ounces daily. To see how long to digest water in your body, see our article on this topic.

Our mission is to get to the bottom of this question, so you and your outdoor companions can travel with peace of mind as long as you are well-prepared. Although dirty, muddy, or cloudy water may not seem very appetizing, it may be all that stands between you and dehydration and possible death.

Reduce the risk of nausea, vomiting, cramps, diarrhea, or contracting potentially fatal viruses by boiling your water to ensure it is safe for consumption. Read further to learn how to determine when water is unsafe to drink, common misperceptions, how to properly boil water, and alternative methods.

Determining Unsafe Water

When you are breathing fresh air and admiring the unadulterated beauty of nature, it may be difficult to imagine that there are millions if not billions of viruses and bacterium surrounding you at all times. Although we cannot always protect ourselves from bugs, the sun, or bad weather, we can be cautious about the water we use and drink while exploring nature.

Water can easily become contaminated by chemicals, oils, sewage, and other pollutants. Bodies of water in or near cities, suburbs, or large populations are all suspect. No matter how isolated you may feel while pioneering a trail you have never hiked before or navigating a foreign stretch of forest, it is highly likely that someone has been there before you.

Wherever people roam, they track contaminates and feces. Animals defecate into bodies of water without second thoughts. Many of us are accustomed to accessing water straight from the tap. Do not allow your habits of assuming all water is safe get the best of your health or sully your adventure.

Unprotected water sources include streams, ponds, rivers, lakes, cisterns, and poorly constructed wells. Major water bottle distributors create advertisements pertaining to natural-source waters that are supposedly pulled from springs, lakes, glaciers, or even rain clouds, or so they would like you to believe.

See also: How to Purify Water with Bleach: Clean Drinking Water in One Step

Even if you get your water from the most idyllic mountain stream on a remote range somewhere, it needs to undergo certain treatments before it is safe enough to ingest. Boiling water is one of the most effective and effortless methods of keeping yourself safely hydrated while you explore new horizons or rough it in the outback.

Although streams and rivers are as unprotected as ponds and lakes, flowing water is preferred to stagnant water if you find yourself in a life-threatening situation. Not only is stagnant water an environmental hazard, but it can also serve as a breeding ground for mosquitoes and other bugs that transmit diseases to humans.

Common Misconceptions

There are many misunderstandings when it comes to sourcing potable water. Contrary to popular belief, rain can contain plenty of harmful chemicals. If you live in or near an urban environment, you can guarantee your local rainfall is far from safe to drink. You would also be ill-advised to try drinking rain runoff from your roof or other surfaces.

Clear, cold, and natural bodies of water are another harmful source for contention. Microorganisms are invisible, so it is impossible for humans to detect whether a body of water is free from bacteria, pathogens, protozoa, viruses, or other contaminants. For a comprehensive review of the Sawyer mini water filtration system, see our article on this.

Even though potable water calls for a rolling boil, it is not necessary to boil your water for a long time. Many campers make the mistake of boiling water for up to 30 minutes, when it only takes a quick boil to kill all of the bacteria and pathogens present in your water supply.

Why Do We Boil Untreated Water?

The water we drink in the comfort of our homes is treated. Water packaged into bottles and sold at our favorite supermarkets is treated. Regardless of how it’s packaged or delivered, drinking water goes through several processes of treatment to ensure it’s potable for the public to drink.

Coagulation, flocculation, sedimentation, filtration, and disinfection are all vital steps in the process of creating clean water. While we’re exploring the great outdoors, however, we don’t have the luxury of easily eliminating contaminants from the water we need to survive. For information on how boiling water purifies it, see our piece on this topic.

Boiling points kill pathogens and other common organisms found in water. The popular method of boiling water is simply more sustainable than treating it another way.

Alternative treatment methods require devices and chemicals while boiling only requires a source of heat and an appropriate vessel. Do not cut corners when it comes to your safety outdoors.

Materials Needed

Finding water should be the first concern of anyone without a readily available hydration supply. You will want to bring along several dynamic tools to easily access water from trees, dry river beds, or rainfall.

After you find your water, you’ll need a convenient way to get it to a rolling boil in order to kill bacteria, pathogens, and other contaminants. Let’s explore the advantages and disadvantages of choosing equipment that can help you find water, heat it, and which heat source is the most reliable.

Finding Water

Tree tapping kits are ideal if you plan to stay in any one camping site for a few days. Shovels or portable gardening tools are excellent for digging for water in dry river beds or other low lying areas. Tarps, tents, or versatile articles of clothing can trap rainwater. Sponges and cloths will help absorb dew and condensation.

Pots with lids are preferred for boiling water, because they reduce the time it takes for your water to boil. In turn, you can use less fuel as you reduce evaporation loss from boiling. One of the most convenient and underutilized tools an outdoor enthusiast can invest in is a rubber hose.

If you intend on traveling through environments where water may be scarce, a rubber hose can help you draw water from otherwise inaccessible sources. A mainstream version of this technology can be found in survival straws, which are small disinfecting tools that allow you to drink directly from contaminated bodies of water.

Thanks to their carbon filter elements, these straws filter out bacteria and pathogens. While these straws are extremely useful tools, they are not practical for large groups or long endeavors.

Boiling Containers

The most essential accessory to pack with you on your journey into the wilderness is either a metal canteen, a pot, or a cup. You can also invest in an affordable, unlined aluminum or steel water bottle. Any of these items are safe and easy to boil water in.

You will want to carry multiple containers depending on the number of people in your group or the number of days you plan to explore. If you’re concerned with achieving the fastest boiling time, you’ll want to consider the material of your boiling container. As a rule, copper is a better heat conductor than stainless steel or aluminum. Disc-based pots are more efficient than cladded pots.

Source of Heat

Boiling your water is as easy as starting a campfire or preparing a portable stove. To build a successful fire, you will need to gather or provide tinder, kindling, and firewood. Open fires continue to withstand the test of time, and many avid outdoor enthusiasts prefer flames as their go-to source of heat.

Alternatively, you can opt for a propane grill, charcoal grill, propane burner, or a solar cooker as a reliable source for heat. Miniature, folding camp stoves tend to have low output and may not be the best resource for anything other than warming or reheating.

Portable butane stoves are efficient, but they do rely on butane canisters that may not fit into your wilderness adventure budget. Solar cookers may be best to use in warmer, sunnier climates.

Propane burners put out an intense heat that may warp the bottom of your container, whereas propane grills are an excellent choice to use, but you should still be cautious of cylinder failure and utilizing this high-maintenance grill in bad weather, such as hurricanes or blizzards.

The Safe Way to Boil Water

Used as a pathogen reduction method, boiling water is one of the safest ways to ensure your drinking water is truly safe to drink while camping, hiking, backpacking, or mountaineering. How long do you boil water to purify it? Bring your water to a rolling boil for about one minute.

Most organisms that are capable of causing diseases are killed in water that reaches 185°F. There are a few circumstances in which you may need to take some extra precautionary steps for the following situations:

High Altitudes (greater than 6,562 feet or 2,000 meters)

The major difference between boiling water at high altitudes versus elevations closer to sea level is that your drinking water needs to cool after reaching a rolling boil. Air pressure is lower at high elevations, so water temperature is also lower. Bring your water to a rolling boil for about three minutes before allowing it to cool off.

Cloudy Water

Whether it’s dirty, muddy, or filled with particles from nature, cloudy water must be treated longer. Some survival experts estimate boiling cloudy water for at least ten minutes to ensure it is suitable to drink. We suggest filtering cloudy water prior to boiling. Save space while packing by utilizing a few small cloths, coffee filters, or paper towels.

Alternatives to Boiling

In a perfect world, you would have clean bottled water or filtered water to look forward to as you’re traversing the forest, the mountain, or wherever your feet take you. Unfortunately, we don’t always find ourselves in the most fortunate of circumstances.

If you find yourself low on fuel or lacking a reliable heat source, you may need to treat your drinking water another way. Let’s explore some of the popular alternative methods for making water safe to drink while exploring the outdoors.

Chemical Treatment

You can easily purify your water by chemically treating it with the help of Halogens such as iodine or regular, unscented chlorine bleach. The major drawbacks to chemically treating your water is that any children traveling with you may be less inclined to drink the disinfected water due to the chemical aftertaste.

Pack flavor additives so your little ones avoid the risk of dehydration and so you can improve the overall experience for everyone involved.


Alternatively, you can equip yourself with a quality filter. Unlike boiling and chemically treating, there’s no wait involved with filtering water. Many bestselling filters include charcoal cartridges that “sweeten” the water to improve the taste.

Should you decide to rely solely on a filter, it may be in your best interest to research any virus concerns in the area where you are hiking or camping. You will need to chemically treat your water even after it is filtered to protect you and your travel companions against harmful viruses.

Ultraviolet Light

Used as the primary source for commercial water treatment, ultraviolet light can effectively reduce pathogens in your drinking water in as little as two minutes. Unlike chemical treatment, ultraviolet technology doesn’t leave any bad aftertastes.

This alternative is especially useful for use with cloudy water. We would not suggest relying on UV as your only source of purifying. However, stock up on a few batteries to keep your device ready-to-go in any extenuating circumstance where an ultraviolet light device comes in handy.


The most important lesson we hope you take from joining us on this journey is that it is safe to assume all water is contaminated. From bacteria to deadly parasites, there are too many opportunities to ingest harmful substances while you are exploring the wilderness.

All that stands between you and a few days or a week of illness is proper preparation and safe practices. Although there are many methods of treating water, none have proved to be as effective at killing bacteria and other contaminants than boiling. Most outdoor enthusiasts and backpackers only pack what they will use.

Save on fuel by remembering that water does not need to boil for ten, five, or even a whole minute. As long as your water is brought to a rolling boil and it reaches a temperature of 185°F, you and your adventure companions can assume it is safe to drink and use.

Just remember, boiling water does not remove chemical toxins. You should avoid chemically contaminated water at all costs, as this will only concentrate those chemicals. Find your water from a reliable source and take every precaution when boiling.

Do you know of any other failsafe methods to ensure water is safe to drink? Do you have suggestions as to how to find water while exploring the outdoors? If so, please let us know in the comments!


3 thoughts on “Does Boiling Water Purify It: Myths and Safe Practices”

  1. What a great article Jerry! I like that you have listed the most common misconceptions about boiling water. This is especially important for those who love hiking and camping adventures like me. Of course I always bring with me clean water, but it is nice to know all of these just in case.

  2. Research suggests that UV light can only be used to purify clear water and not foggy water. If the water is unclear, you should first consider using a pre-filter.


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