Boiling cooking water?

[stilllife]

Question. Do you guys filter all water before you boil it for cooking or do you scoop right out of the stream and pour it in the pot to boil? Just curious.
Thanks

[Another Kevin]

Bringing water to a full rolling boil is enough to disinfect it, so I don't trouble to filter cooking water unless it's turbid or has floaties in it.

[DuneElliot]

Yes, but mostly because the water comes out of the same bottle I'm drinking out of most of the time. Water has to come to a full rolling boil for 5 minutes to be considered safe, not just reaching a boil. That's a lot of extra fuel usage for sterilizing water...I'd rather just filter it to be safe.

[pickNgrin]

You should hold a roiling boil for at least one minute to kill Giardia and other shagnasties.

http://www.cdc.gov/healthywater/drinking/private/wells/disease/giardia.html

[pickNgrin]

Here is a better link for camping: http://www.cdc.gov/healthywater/drinking/travel/backcountry_water_treatment.html

The recommendation is still a rolling boil for 1 min at lower elevations. I had always heard 5 min in my boy scout days. Can't hurt to go a little longer!

[rafe]

What Kevin said. No need to filter water if it's going to be boiled.

[HooKooDooKu]

To keep sanitation procedures KISS...

I only collect water with my 'dirty water' container, and the water from the dirty water container ONLY goes to the filter. All water I use for cleaning, cooking, and drinking only comes from the 'clean water' container.

The only exception is when 'dirty water' is accessed directly from the source for cleaning (such as swimming, rinsing sweaty cloths, dipping a bandanna into cool water to cool off, etc).

[Another Kevin]

You should hold a roiling boil for at least one minute to kill Giardia and other shagnasties.

http://www.cdc.gov/healthywater/drinking/private/wells/disease/giardia.html

OK, rolling boil for 1 minute... I don't usually time the fuel on my alky stove that tightly anyway, and I usually leave the pot on until it burns out. :)

CDC's recommendation is extremely conservative, partly because it takes into account the fact that a lot of people don't actually know the difference between a simmer and a true rolling boil. WHO's recommendations (http://www.who.int/water_sanitation_health/dwq/WSH02.07.pdf) are a lot more liberal:


Although some authorities recommend that water be brought to a rolling boil for to 1 to 5 minutes, the WHO GDWQ recommend bringing the water to a rolling boil as an indication that a high temperature has been achieved. These boiling requirements are likely to be well in excess of the heating conditions needed to dramatically reduce most waterborne pathogens, but observing a rolling boil assures that sufficiently high temperatures have been reached to achieve pathogen destruction. [Link above, p. 13]


I don't think I've boiled water above 2000 metres since I moved back East in 1984.

[nsherry61]

Question. Do you guys filter all water before you boil it for cooking . . .
No. Often don't for drinking either.

[Feral Bill]

I don't pre-treat water I'm boiling anyway.

[SouthMark]

Don't carry a filter so no.

[MuddyWaters]

Yes and no.
It depends on if have excess treated water on me or not.

What you want to know is if its necessary
The answer is no
Heating water to rolling boil is adequate, anything more is just extra

[scrabbler]

I dont because for a lot of meals, drinks, I dont need or want them to be at boiling temps. So I use my energy filtering the water ahead of time, and just heat it to the temp I need for the food or drink I'm about to consume. I think this saves fuel, and wastes time filtering. It's what I choose. HYOH.

[jjozgrunt]

It would be nice to think that all water in the mountains is clean and good to go, but a recent photo on Guthooks FB page of tp in a creek should turn you off that thinking. The busier a trail is the more chance the water has been fouled, IMO. Personally if it was coming out of a spring, at my feet, I probably wouldn't treat it at all. Other wise I use a sawyer squeeze and if I'm boiling I only have to just get it there and don't have to wait 1,2,5 or whatever the current teaching is for a rolling boil. Saves fuel.

[Maydog]

212 degrees isn't the magic number. Most bacteria and viruses are dead at 140 degrees; to be extra-safe, 180 degrees is sufficient to make water biologically safe to consume. Once it reaches a rolling boil, it has been at 180 for probably 2-3 minutes.

[LIhikers]

Years ago my wife and I met a hiker named DocDel, or maybe DelDoc, anyway, a doctor from Delaware.
He said that 180 degrees was an adequate temperature to bring your water to that would make it safe to consume.
I asked him how to know when it reached 180 and he stated that if the bottom of the pot was covered in bubbles you would be good to go.

[Uncle Joe]

I cook with filtered water. You filter for a reason.

[Lyle]

Just one more documentation that bringing the water TO a boil is sufficient, anything more is most likely overkill and just adds a "margin of safety". I just bring my untreated water to a boil and go for it - never had any illness that I attributed to contaminated water in well over 30 years of backpacking.

From: "Wilderness Medicine, Fifth Edition" by Paul S. Auerbach, MD, MS, pages 1377-78.
" The boiling time required is important when fuel is limited. The old recommendation for treating water was to boil for 10 minutes and add 1 minute for every 1000 feet in elevation. However, available data indicate this is not necessary for disinfection. Evidence indicates that enteric pathogens are killed within seconds by boiling water and rapidly at temperatures above 60* C (140* F). In the wilderness, the time required to heat water from 55* C (131* F) to boiling temperature works toward disinfection. Therefore, any water brought to a boil should be adequately disinfected. An extra margin of safety can be added by boiling for 1 minute or by keeping the water covered for several more minutes, which will maintain high temperature without using fuel, or by allowing it to cool slowly. Although the boiling point decreases with increasing altitude, this is not significant compared with the time required for thermal death at these temperatures. In recognition of the difference between pasteurizing water for drinking purposes and sterilizing to kill all microbes, including spores, for surgical purposes, many other sources, including WHO, now agree with this recommendation to simply bring water to a boil. Because of scant data for hepatitis A, the Centers for Disease Control and Prevention (CDC) and the EPA still recommend boiling for 1 minute to add a margin of safety. Other sources still suggest 3 minutes of boiling time at high altitude to give a wide margin of safety."

[Traveler]

It would be nice to think that all water in the mountains is clean and good to go, but a recent photo on Guthooks FB page of tp in a creek should turn you off that thinking. The busier a trail is the more chance the water has been fouled, IMO. Personally if it was coming out of a spring, at my feet, I probably wouldn't treat it at all. Other wise I use a sawyer squeeze and if I'm boiling I only have to just get it there and don't have to wait 1,2,5 or whatever the current teaching is for a rolling boil. Saves fuel.

Adding to this, in much of the eastern United States, lack of rain has and is creating several problems, drought being one. Fecal material in the forest is not able to break down quickly without some precipitation, if it comes in torrents, it can be carried downhill, which can impact otherwise good surface water sources. Spending a few minutes filtering water, even for cooking purposes, reduces the potential for fecal contaminates reaching you. Its a personal choice, some never filter, some filter all the time. Having suffered through some bad water experiences, I prefer the safer route of filtration.

[garlic08]

I'd put pre-treating your cooking water firmly in the "belt and suspenders" category. And that's fine if you're willing to tote the fuel, or put the extra wear/use on your water treatment system.

I'd long ago read the quote Lyle provided in post 18, and since then I no longer waste the fuel on a rolling boil. Especially if you're simmering rice or pasta, that's ten or twenty minutes at very high temps for anything biological.

On a long hike, you not only need to consider fuel consumption, but the life of your water treatment method. You're only going to get so many units out of whatever you use before it runs out, clogs up, or breaks.

[peakbagger]

From a fuel use perspective the amount of energy required to get boil is quite a bit more than bringing the water up to near boil. Water needs 1 Btu to raise the temperature of a pound of water 1 degree F. It takes roughly 1000 btu's per pound to boil water. I avoid boiling unless needed by the recipe. Assuming 60 degree water and raising to 160 degrees, I can kill all the nasties in 10 pounds of water for the same energy use as boiling 1 pound of water. No brainer to me.

[10-K]

First I want to go on record stating that it's never a mistake to filter water. With that out of the way....

As a rule, I don't filter or treat in the southern Appalachians. I carry a few MSR purification tablets but that's it and I've had the same pack of tablets for 2 years if that tells you anything.

On unfamiliar trails I take a lifestraw and aquamira. Hand operated water filters are just something else to carry and malfunction.

And if you're going to filter your water be aware of cross contamination. If you watch someone filter water almost always you'll see that they don't pay attention to that which kind of defeats the purpose.

[pickNgrin]

The reason that boiling is the guideline is that it eliminates all guesswork. There is no estimating the water temperature. There is no thermometer to misread, break, get damaged, or become uncalibrated. If you observe the boil, then you are guaranteed by physics to be at or near 212F (depending on a known altitude correction). Mother Nature don't lie!

If you decide to be "smarter" than the time-proven, scientifically determined guidelines, then you would be wise to carry a good thermometer and make sure that it reads correctly. The only ways that I know to do this are to compare it against a known thermometer (there's a chicken-and-egg problem there), or to test it by physics at home. Make sure that it reads the boiling point and freezing point correctly by placing it in boiling water and also in an ice water bath. Obviously it should read 212F and 32F respectively. It is does those things right, it is a good bet that it reads properly in between.

[garlic08]

The reason that boiling is the guideline is that it eliminates all guesswork. There is no estimating the water temperature....

True, but...I would posit that if the water is hot enough, long enough to cook a pot of pasta, it's hot enough to kill the nasties.

But if you're just having coffee or tea, then I would agree a layer of bubbles forming on the bottom of the pot is not accurate enough.

[nsherry61]

From a fuel use perspective the amount of energy required to get boil is quite a bit more than bringing the water up to near boil. Water needs 1 Btu to raise the temperature of a pound of water 1 degree F. It takes roughly 1000 btu's per pound to boil water. I avoid boiling unless needed by the recipe. Assuming 60 degree water and raising to 160 degrees, I can kill all the nasties in 10 pounds of water for the same energy use as boiling 1 pound of water. No brainer to me.
But peakbagger, That 1000 btu's is to boil away that pound of water by turning it all into steam. I takes no more energy to bring water from 1 degree below boiling to boiling than it does to bring that same water from 50 degrees to 51 degrees.

[pickNgrin]

But peakbagger, That 1000 btu's is to boil away that pound of water by turning it all into steam. I takes no more energy to bring water from 1 degree below boiling to boiling than it does to bring that same water from 50 degrees to 51 degrees.

Not exactly true, because some energy is required to convert the water to steam as the water boils. This is known as "latent heat".

[peakbagger]

The latent heat of vaporization at standard conditions is 1000 btu/lb. That's what it takes to get the liquid water to change to vapor. When you see bubbles coming off the bottom its a waste of fuel. The "bugs" are long since dead. Of course steam has a lot lower density than liquid water so a little bit of liquid water creates a whole lot of steam. BTW, the specific heat of water is not constant over the range of liquid water, the difference isn't a lot but its not a constant so the amount of energy required to raise 1 pound of water from 50 to 51 is different than 210 to 211.

[nsherry61]

. . . When you see bubbles coming off the bottom its a waste of fuel. . .
So don't hold your boil, but go ahead and bring it to boiling.


. . . The "bugs" are long since dead. . .
Maybe the mosquitoes and flies are dead. And surely, some of the microorganisms as well. BUT, absolutely not all of the microbes are dead. If boiling for a full minute kills everything of concern, probably bringing to a boil and then letting it sit at temperature in a cozy for a minute would be nearly the same effectiveness. However, bringing the water to 160 degrees would not be close to as effective.

FYI: Milk is pasteurized under pressure at well above boiling because hotter than boiling is more effective than boiling temperatures (also higher heat for shorter periods changes the flavor of milk less than lower heats for longer). And, if one still thinks everything is killed by boiling, we culture some deep-sea bacteria inside autoclaves (>250 degrees F) because boiling isn't hot enough for them to grow.


. . . BTW, the specific heat of water is not constant over the range of liquid water, the difference isn't a lot but its not a constant so the amount of energy required to raise 1 pound of water from 50 to 51 is different than 210 to 211.
Are we really digressing to an argument over 0.008 degrees C when the boiling point of water changes by 20 times that much for every 1000 feet of elevation change (+/- a little I'm sure). :rolleyes:

[rocketsocks]

The latent heat of vaporization at standard conditions is 1000 btu/lb. That's what it takes to get the liquid water to change to vapor. When you see bubbles coming off the bottom its a waste of fuel. The "bugs" are long since dead. Of course steam has a lot lower density than liquid water so a little bit of liquid water creates a whole lot of steam. BTW, the specific heat of water is not constant over the range of liquid water, the difference isn't a lot but its not a constant so the amount of energy required to raise 1 pound of water from 50 to 51 is different than 210 to 211.1 cu. inch of water will expand to 1,728 cu. of steam IIRC

[rocketsocks]

So don't hold your boil, but go ahead and bring it to boiling.


Maybe the mosquitoes and flies are dead. And surely, some of the microorganisms as well. BUT, absolutely not all of the microbes are dead. If boiling for a full minute kills everything of concern, probably bringing to a boil and then letting it sit at temperature in a cozy for a minute would be nearly the same effectiveness. However, bringing the water to 160 degrees would not be close to as effective.

FYI: Milk is pasteurized under pressure at well above boiling because hotter than boiling is more effective than boiling temperatures (also higher heat for shorter periods changes the flavor of milk less than lower heats for longer). And, if one still thinks everything is killed by boiling, we culture some deep-sea bacteria inside autoclaves (>250 degrees F) because boiling isn't hot enough for them to grow.


Are we really digressing to an argument over 0.008 degrees C when the boiling point of water changes by 20 times that much for every 1000 feet of elevation change (+/- a little I'm sure). :rolleyes:i think your right about some bugs, botulism needs to be held at 212 degrees for several min. to render it inoperable. IIRC

[swjohnsey]

Did y'all read the article about letting you kids eat dirt?

[MuddyWaters]

First I want to go on record stating that it's never a mistake to filter water. With that out of the way....


Yes, theoretically, except that filters, ALL of them , will fail or plug eventually, so that the less one is used, the more likely it will be there when really needed.

Just my experience.
Which is why I only use AM as well 98% of time

Stay away from pond sources and not much need for one on AT imo.

If theres stagnant water and livestock around......i want a filter too for nasty sources, realizing it has limited life and prefiltering/settling is required to prolong it. Drink mix required too to cover up taste, smell, and water color even.

Ive gotten really sulfurous water before too in NM, that was so smelly I couldnt drink it without strong drink mix. Cooking with it would ruin food.

[cmoulder]

I've been forced more than a few times to drink some really stanky standing water treated with AM and have never gotten sick. Just last weekend I drank AM-treated stagnant water from Lilypad Pond in the Pharaoh Wilderness of the Daks and am not yet sick, knock wood. The water tasted like dirt, but I find that if I hold my nose while drinking nasty water the taste is not nearly as bad. I give really nasty water a couple extra drops of AM, for sure, and wait longer than the recommended treatment period to use. However, I feel okay about not treating it with AM but bringing it to a full, rolling boil and dumping it into my FD dinners... never been sick from that, either.

[Venchka]

So when I was preparing dinner earlier this month at 11,000 ++ feet, according to the Dark Ages rules, I should have boiled my water for 21 minutes.
Right.
Didn't happen.
Therefore I must have died.
Wayne


Old. Slow. "Smarter than the average bear."

[dudeijuststarted]

I've heard the privy works as an excellent aquifer for filtration if you have time to wait

[KDogg]

I used a sawyer squeeze for the entire trail. Always filtered cooking and drinking water and never worried about contamination or wether I should treat or not. I'd never waste fuel by boiling an extra minute (or five, whatever the case is). Depending on your stove this could make a big difference in fuel use. The Sawyer did start to clog towards the last two weeks of my thru as it did for others that I was hiking with. You can still use it when it starts to clog but your squeeze bottles will also start to fail due to the excess pressure required to filter. My group had four bottles between us and only one was intact on Katahdin.

Some folks like the tablets to disinfect but I found that many switched to the Sawyer over time. We hit rain in the Smokeys and all the water sources were brown with mud. The filters had no problem getting rid of this.

[nsherry61]

Just a couple (okay, 4) thoughts about common water safety misconceptions . . .
1) Pond water is not necessarily bad or even worse than running water. If the pond is calm and has been in the sun for a few hours, the top couple inches in the surface layer will be well sterilized by the sun's UV and will actually be cleaner and safer water than a clear running stream. The trick is collected from just the top few inches while avoiding and surface scum. If you haven't already learned, stick a hard bottle, narrow mouth is easier, open end first through the surface of the water so air pressure keeps the water from filling the bottle. Then gently turn the bottle right side up under water while keeping the opening just below the surface of the water while it fills. Done. Clean water, naturally sterilized, from a lake or pond!
2) Small amounts of contamination by dirty water is rarely an issue. Most of us have functioning immune systems and it takes significant contamination to actually lead to infection. In reality, just rinsing out a dirty bag with clean water is clean enough to reduce the risk of significant contamination to almost zero. And, cleaning dirty threads on a bottle cap is unlikely to ever be necessary.
3) Many of use have hiked 1000's of miles and spend many 100's of days and nights outside without ever treating any of our water and never getting sick. So, the likelihood of any one, relatively clean appearing, source getting anyone sick is unlikely (although it is always that one clean source you didn't treat that seems to get you sick).
4)Don't ever think that because you haven't gotten sick your treatment method is working. You are unlikely to have ever gotten sick even if you didn't treat your water at all.

[Traveler]

Just a couple (okay, 4) thoughts about common water safety misconceptions . . .

4)Don't ever think that because you haven't gotten sick your treatment method is working. You are unlikely to have ever gotten sick even if you didn't treat your water at all.

Agreed with most of what you said, and not taking a shot here by any means, however on number 4, I disagree. I would say if one treated water all the time and have not gotten sick, the method is working for them, as evidenced by the lack of incident(s). Prevention is designed to stop something from occurring and its success essentially measured by events that do not happen.

A good example would be flu vaccination. I used to get flus often, every two to three years or so when I was younger. Since I started getting annual flu shots at 35, I have not had a flu since. Saying "don't ever think because you haven't gotten a flu since your prevention method started, the method is working" would be flawed given the results where many others that did not get flu shots were taken ill by it.

Some people are sickened by water they don't treat. If treatment prevented ingestion at any water source, even if just one, by definition the preventive method would be working. Obviously there can be a lot of luck involved in not treating water, which there are a lot of people claiming water treatment is not necessary due to that "right place/right time" luck. Some people can contract parasites but never feel symptoms and become carriers that impact others. Since they don't feel sick they would claim to not have been taken ill by water as well. But, there is more to this than parasites.

Perhaps picking a nit here, however, my concern with this issue is related to the drought in the Eastern US (and other regions of the US), which is getting severe in some areas. There has been an increase in fecal bacteria counts following rain events in places that routinely test for this and do not have similar high count results in years when precipitation is average. Many of these test sites are at lakes and ponds and streams around reservoirs that receive run off water from rain events. Since fecal matter needs precipitation to break down, without it, breakdown is much slower and increases fecal contact with any run off rain water, elevating bacteria counts following local rain events. Extrapolation is not hard to understand if these readings are higher where measured, they are probably higher everywhere in the area/region, washing into surface water collection points like ponds and brooks that are sources for hiker water. What was safe two years ago to drink without treating may not be safe today as a result.

[nsherry61]

. . . I would say if one treated water all the time and have not gotten sick, the method is working for them, as evidenced by the lack of incident(s). . .
That's not entirely different than suggesting that since I wear a tin foil hat to avoid being abducted by aliens, and I haven't been abducted by aliens, my tin foil hat is working. . . I don't think that logic holds.


. . . A good example would be flu vaccination. I used to get flus often, every two to three years or so when I was younger. Since I started getting annual flu shots at 35, I have not had a flu since. . .
Again, I disagree. This is not a good example. In the vaccine case, you started with a problem and reduced it with an effective practice. Therefore, it is reasonable to assume your practice worked.

In the case of water treatment, unless you have been getting water born diseases in the past and after treatment quit getting sick, there is no way to know whether you are staying healthy because of your treatment or because you have never encountered the infectious element.

Please, don't take this to suggest that I think treading water is silly or uncalled for. There is plenty of evidence and there are plenty of examples of people getting sick from untreated water. And, there are many well tested ways to treat water and make it safe.

BUT, unless you have been sick several times in the past and found that your treatment method (whatever if may be) has eliminated illness consistently when used under similar circumstances where you got sick in the past, you cannot suggest that there is any evidence your treatment works based on your experience. In fact, most people in most back-country settings will not get sick repeatedly drinking untreated water.

In the end, use well tested and prescribed methods for water treatment, or don't. Whatever you want. BUT do not suggest that any water treatment shortcuts are still effective just because you haven't gotten sick while using them!

[Traveler]

That's not entirely different than suggesting that since I wear a tin foil hat to avoid being abducted by aliens, and I haven't been abducted by aliens, my tin foil hat is working. . . I don't think that logic holds.


In the end, use well tested and prescribed methods for water treatment, or don't. Whatever you want. BUT do not suggest that any water treatment shortcuts are still effective just because you haven't gotten sick while using them!

Not sure I am following your logic, I have been made ill by water before (parasite and bacterial issues), since I have filtered as a routine I have not. So in my instance, filtering is working for me. Thats why I used the vaccine example.

I didn't suggest short cutting water treatment (or not using it at all) may not be effective, only that it raises the potential of contracting something treatment prevents with drinking water. One could have the same admonishment of not suggesting any water treatment short cuts are effective just because someone did not get sick using them or not treating water.

The overarching point was water sources this year is drought related (moderate to severe in various parts of New England and the Eastern US) given the higher level of fecal bacteria being measured lately after rain events may render water sources bad that one may have used without treatment in prior average rainfall years.

[nsherry61]

Not sure I am following your logic . . .
I think we are probably not in disagreement here.

I just get tired of people suggesting that whatever method they use to purify water works because they haven't gotten sick. When, in reality, they probably didn't get sick because either their water treatment works reliably or they have never come in contact with enough contagion to get sick. And, if one has never gotten sick from water, they have no way of knowing if the reason they didn't get sick was luck or water treatment.

I've never gotten sick, to my knowledge, from drinking untreated water, and I grew up and spent most of my adult life drinking untreated back-country water.
Now, it may be that I was lucky. It may be that I wasn't lucky, because most people in my situation would not have ever gotten sick because illness is just not all that common from back-country water in North America. It also may be that I not only got sick and didn't realized it was from water a drank two weeks earlier, but I could be a carrier of water-born disease and not know it because my infection is low enough grade that I am not bothered by it.

We don't know.

BUT, I am NOT going to suggest that not treating back-country water is safe just because that is what I have done and it works for me. . . although, I do suggest that our culture has more fear (a perception of higher risk) of back-country water contamination than is suggested by actual measurement. . . kinda like our fear of bears or rattlesnakes.

In other words, take reasonable precautions (depending on your risk aversion) but don't get all stressed about it.

[Another Kevin]

i think your right about some bugs, botulism needs to be held at 212 degrees for several min. to render it inoperable. IIRC

That's foodborne, not waterborne. (In fact, C. botulinum is a really difficult bug to deal with. Unless foods are really acidic, they need long processing at temperatures ABOVE 212 degrees to make them safe. That's why jams, jellies, pickles, tomatoes and sauerkraut can be canned in a boiling-water canner, while most other stuff needs a pressure cooker.)

But C. botulinum doesn't make water unsafe. It isn't the bug that gets you there, it's the toxin that's produced when the bug has been living in food for a while.

[Another Kevin]

BUT, I am NOT going to suggest that not treating back-country water is safe just because that is what I have done and it works for me. . . although, I do suggest that our culture has more fear (a perception of higher risk) of back-country water contamination than is suggested by actual measurement. . . kinda like our fear of bears or rattlesnakes.

In other words, take reasonable precautions (depending on your risk aversion) but don't get all stressed about it.

Very good advice!

Where I've given recommended practices, I've followed WHO guidelines, not anecdote. For whatever reason (and there are several reasons, good and bad), the CDC guidelines are more conservative.

Note that the 160 degree temperature for water pasteurization requires a fairly long time at temperature (some sources say twenty minutes, some even recommend several hours) to be effective, while bringing the water to a full rolling boil doesn't require particular precautions to maintain temperature. Pasteurization is recommended chiefly because in many parts of the developing world it can be achieved without needing fuel, simply by leaving water containers exposed to the Sun. (And the UV will surely not hurt, if a clear container is used.)

[Hikingjim]

If it's ice cold water or temps I will sometimes use filtered water so that I don't worry about a rolling boil, etc
If it's just summer and the water looks debris-free, then a couple minutes boiling isn't going to take any time and that works for me

[QiWiz]

If I know I'm going to boil it, I do not treat the water; just scoop it out of stream using the pot I'm going to cook in.