Boiling water, video by the Author.
For more on water disinfection and boiling read “Water
Disinfection: When is boiled, boiled enough…? ©”, HERE
and “True or False, You Should Drink
Water From The Spring Where Horses Drink?©”, HERE
– Author’s note.
The five
stages of boiling...
 |
Graphic by the Author.
In undisinfected water
there can be three different kinds of pathogens that are harmful to humans:
protozoa, bacteria, and viruses.
Protozoa that commonly found in water, and that are harmful to humans,
are cryptosporidium and giardia intestinalis (also called giardia lamblia), while commonly
occurring, harmful bacteria are campylobacter,
salmonella, shigella and escherichia coli,
and harmful viruses often found in water are enterovirus, hepatitis A, norovirus,
and rotavirus.
Per
the CDC (Centers for Disease Control and Prevention), boiling water is the best
method to disinfect water2 by destroying dangerous pathogens and
making it safe to drink, even when it is turbid or cloudy, or you are at a high
altitude.
Without
using a thermometer, a rolling boil is the only absolute, easily recognizable,
visual clue to the temperature of water.
However, as you are heating water there are some other visual clues to
the temperature of the water as it is heating.
This is important because, while most pathogens in water are killed at
temperatures well below the boiling point of water, the hepatitis A virus is heat resistant and can only be destroyed by
water heated to a rolling or full boil.
 |
Water less than 160o F (72o C), photograph by the Author.
Bubble
do not begin to appear at the bottom of the pan until the water reaches about162o
F (72o C). If you heat
water and keep it at 145o F (63o C) for thirty minutes “the
enteric pathogens will be significantly reduced, likely
to potable levels”1,
by what is called “vat pasteurization”.
However, the problem with “vat pasteurization” in the field, is that
there are no visual clues to the water’s temperature and without a thermometer you
won’t know what the temperature of the water is.
Stage
One...Shrimp Eyes
 |
Stage one of boiling, tiny bubbles appear at the bottom of the pan, photograph by the Author.
In
stage one of boiling, tiny bubbles begin to appear at the bottom of the
pan. At this point the water about 160o
to 162o F (71o to 72o C) and if the water is
kept at this temperature for 15 seconds it will be pasteurized, and the enteric pathogens will be reduced to potable levels.
Stage
Two...Crab Eyes
 |
Stage two of boiling, the bubbles become slightly larger, photograph by the Author.
At stage two of boiling, the water
is about 175o F (80o C), and the bubbles are lightly
larger, also wisps of steam begin to rise.
Stage Three
... Fisheyes
 |
Stage three of boiling, the bubbles at the bottom of the pan are about the size of fisheyes or small pearls, photograph by the Author.
At
stage three of boiling, the water has reached the temperature of about 180o
F (82o C) and the bubbles at the bottom of the pan are about the
size of fisheyes or small pearls. Also,
there is more rising steam.
Stage Four
... Ropes of Pearls
 |
Stage four of boiling, the bubbles stream to the surface like a rope of pearls, photograph by the Author.
In
stage four of boiling, the bubbles stream to the surface like a rope of pearls
and the temperature of the water is between 200o to 205o
F (93o to 96o C).
At these temperatures it will take between .1 and .05 seconds for the enteric
pathogens to be reduced to potable levels and the water to be disinfected.
Stage Five
... Raging Torrent
 |
Stage five of boiling, a raging torrent or a rolling boil, photograph by the Author.
At
stage five of boiling, the water is a raging torrent, a rolling or a fast boil
and has reached the full boiling temperature of 212o
F
(100o C). At this temperature
it will take between .01 seconds for the enteric pathogens to be reduced to
potable levels and the water to be disinfected.
Boiling, “100%
effective in removing all pathogens”
CDC
(Centers for Disease Control and Prevention)
The CDC states that “Except for boiling, few of the water
treatment methods are 100% effective in removing all pathogens”. The CDC also suggests that prior to boiling,
cloudy water should be filtered through clean clothes, or left to settle,
before drawing off the clear water for boiling.
Research by Howard D.
Backer, MD in 1996, the CDC in 2009 and the World Health Organization (WHO) in
2011 has shown that pathogens are killed rapidly by water hotter than 140o
F (60o C). In fact, the
research shows that the time it takes to heat water on a stove or over a fire,
from 131o F (55o C) to a rolling boil of 212° F (100° C)
at sea level, will kill all disease-causing bacteria, viruses, and protozoa,
and therefore disinfect the water and make it potable. According to the CDC, heating water to
rolling boil water for just one minute is “high
effectiveness in killing” protozoa such as Cryptosporidium, Giardia
intestinalis (also called Giardia
lamblia), bacteria like Campylobacter,
Salmonella, Shigella and E. coli, and
viruses such as enterovirus, hepatitis A, norovirus, or rotavirus.
So, just to
be safe...
 |
Graphic by the Author, from Water Disinfection for International and Wilderness Travelers, by Howard D. Backer, MD, pages 357 to 358.
Because of the heat
resistance of the Hepatitis A virus, however,
the CDC recommends heating water to a rolling boil for one minute, and for an
additional three minutes at elevations above 2,000 meters (6,562 feet), to
ensure that the water has remained hot enough, for long enough, to destroy any
dangerous pathogens3. So,
even if the enteric pathogens are destroyed at temperatures below 212o
F (100o C), just to be safe always bring your water to a rolling boil
before you drink or rehydrate food with it.
For
more on what to do with that nice pot of boiled, and now disinfected, water,
read “Drinking Black Tea to Stay Hydrated...Say What?! ©”, HERE,
“Coffee, Tea or … Chocolate? Part One ©”, HERE;
“Coffee, Tea or … Chocolate? Part Two ©”, HERE;
“Coffee, Tea or … Chocolate? Part Three ©”, HERE;
or “Coffee, Tea or … Chocolate? Part Four ©”, HERE.
Don’t forget to come back next week and read “...no soldier should
drink any water without it being boiled...©”, where we will talk about water
disinfection during the late 18th and early 19th
centuries.
 |
Photograph by the Author.
I
hope that you continue to enjoy The Woodsman’s Journal Online and look for me
on YouTube at BandanaMan Productions for other related videos, HERE. Don’t forget to follow me on both The
Woodsman’s Journal Online, HERE,
and subscribe to BandanaMan Productions on YouTube. If you have questions, as always, feel free
to leave a comment on either site. I
announce new articles on Facebook at Eric Reynolds, on Instagram at bandanamanaproductions,
and on VK at Eric Reynolds, so watch for me.
That
is all for now, and as always, until next time, Happy Trails!
Notes
1 What
is disinfection, is it the same thing as sterilization or pasteurization? And what exactly does potable mean? Disinfection means the removal or destruction
of harmful pathogens and is the desired result of water treatment in the field,
where it is typically accomplished by boiling.
Pasteurization is like disinfection but involves lower
temperatures over a longer time than disinfection. The goal of both disinfection and
pasteurization is to create potable water, which means that the water has a
minimal microbial hazard. Sterilization
is the destruction or removal of all life forms and is required for surgical
purposes. Sterilization for surgical
purposes requires that the water and the items to be sterilized, be brought to
a rolling boil for 15 to 20 minutes.
2 “Effect of Heat on the Sterilization of
Artificially Contaminated Water”, by Howard D. Backer, page three
3 An
excerpt from “Water Disinfection: When is boiled, boiled enough…? ©”, HERE.
 |
Graphic by the Author
The CDC recommends the
additional three minutes of boiling time because, at sea level the boiling
point of water is 212o F (100o C), however, as elevation
increases, atmospheric pressure decreases and water boils at lower
temperatures. For every 500-foot (153
meter) increase in elevation, the boiling point of water decreases by just
under 1o F (approximately .5o C). For this reason, the CDC recommends boiling
water to a rolling boil for an additional three minutes at altitudes greater
than 2,000 meters (6,562 feet). These
additional minutes of rolling boiling time at higher altitudes are intended to
ensure that even at these higher elevations, enough boiling time is achieved to
ensure the destruction of any pathogenic organisms in the water.
Similarly, the National
Wilderness Conference advocates bringing water to a rolling boil for one minute
at sea level and boiling it for an additional one minute for every 1,000 feet
(305 meters) above sea level, to ensure that dangerous pathogens are
destroyed. It will be noticed that the
National Wilderness Conference is more cautious than the CDC, as it advocates
bringing water to a rolling boil for an additional minute for each 1,000-foot
(305 meters) increase in elevation above sea level.
These additional minutes
of rolling boiling time at higher altitudes are intended to ensure that even at
these higher elevations, enough boiling time is achieved to ensure the
destruction of any pathogenic organisms in the water.
The CDC and the WHO, now
agree that boiling water for drinking purposes for ten minutes is unnecessary;
and in fact, it is a waste of time, fuel, and water since, water cannot become any hotter than 212°F
(100°C) and remain in a liquid state. To
continue to heat water once it has reached the boiling point, more than one
minute at low elevations and an additional three to six minutes at elevations
above 2,000 meters (6,562 feet), merely wastes fuel, water, and time; all of
which might be in short supply in a survival situation. So, boil your water only as long as the CDC
recommends or if you prefer to be extra cautious, use the National Wilderness
Conference’s recommendation, and then your water will be boiled enough.
Sources
Backer,
Howard D.; “Effect of Heat on the Sterilization of Artificially Contaminated
Water”, [Journal of Travel Medicine; 1996] p. 3:1-4 https://academic.oup.com/jtm/article/3/1/1/1804390, accessed December 22, 2021
Backer,
Howard D.; “Field Water Disinfection”, https://aneskey.com/field-water-disinfection/, accessed April 23, 2019
CDC, “A Guide to Drinking
Water Treatment and Sanitation for Backcountry & Travel Use”, [2009] http://www.cdc.gov/healthywater/drinking/travel/backcountry_water_treatment.html,
accessed August 31, 2015
Curtis, Rick; The
Backpacker’s Field Manual, http://www.princeton.edu/~oa/manual/water.shtml,
accessed August 31, 2015
Howard, “Boiling Water Verses
Pasteurization to Make Safe Drinking Water”, March 19, 2015, [© 2021
Preparedness Advice], https://preparednessadvice.com/boiling-water-verses-pasteurization-make-safe-drinking-water/, accessed December 20, 2021
Green-Golden, Sharon;
“Boiling: The Answer to High-level Disinfecting of Surgical Instrumentation in
a Village of a Third World Country”, [2009] https://www.iahcsmm.org/images/News/Fellow_Papers/FellowshipPaper_SharonGrGolden__2009.pdf,
Accessed May 3, 2019
The Engineering Toolbox,
“Pasteurization Times and Temperatures”, https://www.engineeringtoolbox.com/pasteurization-methods-temperatures-d_1642.html,
accessed December 20, 2021
“The 5 Different Stages
of Boiling Water and How the Chinese Use Them for Tea”, [© 2021 Golden Moon
Tea], https://www.goldenmoontea.com/blogs/tea/106687623-the-5-different-stages-of-boiling-water-and-how-the-chinese-use-them-for-tea,
accessed December 20, 2021
Wood, T. D.; “Water
Treatment for International Travel”, http://www.rei.com/learn/expert-advice/water-treatment-international.html#Boiling,
accessed September 30, 2015
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