[Slackjawls]

My tap water is treated with chlorine.  You can smell it and taste it but it is a moderately low level.  I treat my brewing water with campden tablets.  Is there any impact from the campden tablets on my brewing water chemistry that I need to consider?  I use Bru'n water v5.5 to build my water profiles and I don't see any comment or info. on the effects of adding potassium metabisulfite to my water.

An interesting side note:  I have talked to several professional brewers in my town and they all say they do nothing to treat for the chlorine in the water.  No pre-boiling, no filtering, and no chemical treatment.  Which begs the question, "Is it really necessary to treat for chlorine at all?"

[dmtaylor]

Removal of chlorine is very important to prevent the off-flavor known as chlorophenol, which tastes like Band-Aids or disinfectant -- very nasty when it happens, and it's happened to me and to millions of others.  And it's so easy to prevent.

I recently heard that this small dose of Campden will reduce pH by about 0.02 and will increase sulfate by just 4 ppm or something in that ballpark, which in both cases is truly negligible and can safely be ignored.

[a10t2]

If it's chlorine (as opposed to a chloramine) then it can be treated with Campden, but can also be off-gassed simply by heating the water up to strike temperatures.

Like Dave said, the impact of the Campden at proper dosing rates (each tablet treats 20 gal) is negligible.

[RC]

If it's chlorine (as opposed to a chloramine) then it can be treated with Campden, but can also be off-gassed simply by heating the water up to strike temperatures.

Yup, the reason the pro brewers in your town can get away with not worrying much about chlorine in their source water is because the chlorine will gas off in the mash and boil. What's one of the ways to rid water of chlorine? Boil it. What do we do with wort? Boil it. And they probably have their brewing water sitting in a vented HLT at ~180 degrees. So there's not much to worry about with chlorine in brewing water (although, out of prudence, my brewing water always goes through a carbon filter first...)

Chloramines are different, they don't boil off. Chloramines could be the source of chlorophenol in a beer, but so too could be infection by wild yeast.

[denny]

If it's chlorine (as opposed to a chloramine) then it can be treated with Campden, but can also be off-gassed simply by heating the water up to strike temperatures.

Yup, the reason the pro brewers in your town can get away with not worrying much about chlorine in their source water is because the chlorine will gas off in the mash and boil. What's one of the ways to rid water of chlorine? Boil it. What do we do with wort? Boil it. And they probably have their brewing water sitting in a vented HLT at ~180 degrees. So there's not much to worry about with chlorine in brewing water (although, out of prudence, my brewing water always goes through a carbon filter first...)

Chloramines are different, they don't boil off. Chloramines could be the source of chlorophenol in a beer, but so too could be infection by wild yeast.

The problem is that by the mash and boil, the chlorophenols have already formed.

[dmtaylor]

Yup, the reason the pro brewers in your town can get away with not worrying much about chlorine in their source water is because the chlorine will gas off in the mash and boil. What's one of the ways to rid water of chlorine? Boil it. What do we do with wort? Boil it. And they probably have their brewing water sitting in a vented HLT at ~180 degrees. So there's not much to worry about with chlorine in brewing water (although, out of prudence, my brewing water always goes through a carbon filter first...)

Respectfully, I must inform you that you misunderstand... Chlorine is highly reactive and MUST be removed PRIOR to coming into contact with the grist in the mash.  Grains contain phenolic compounds, and in presence of chlorine produce the chlorophenols fairly quickly.  So it's important to get the chlorine out of the water prior to combining with the grains.  After the reaction of chlorine and phenol has occurred, it's too late and you won't be able to get it all out during the mash and boil.  Chlorophenol is volatile, but unfortunately not volatile enough to get rid of all of it in the mash and boil.

[RC]

Yup, the reason the pro brewers in your town can get away with not worrying much about chlorine in their source water is because the chlorine will gas off in the mash and boil. What's one of the ways to rid water of chlorine? Boil it. What do we do with wort? Boil it. And they probably have their brewing water sitting in a vented HLT at ~180 degrees. So there's not much to worry about with chlorine in brewing water (although, out of prudence, my brewing water always goes through a carbon filter first...)

Respectfully, I must inform you that you misunderstand... Chlorine is highly reactive and MUST be removed PRIOR to coming into contact with the grist in the mash.  Grains contain phenolic compounds, and in presence of chlorine produce the chlorophenols fairly quickly.  So it's important to get the chlorine out of the water prior to combining with the grains.  After the reaction of chlorine and phenol has occurred, it's too late and you won't be able to get it all out during the mash and boil.  Chlorophenol is volatile, but unfortunately not volatile enough to get rid of all of it in the mash and boil.

I’m not arguing against the brewing chemistry written in textbooks. But I wish someone could explain this to me: Where I used to work, due to a (temporary) lack of QC we brewed three beers using unfiltered, chlorinated municipal tap water, not being aware that the carbon filter was broken. Not the faintest hint of chlorophenols in the finished beers. I infer that the pro brewers mentioned in the original post have had the same experience.

Perhaps all the chlorine gassed off due to the temp of the mash, perhaps there weren’t many phenols available to react because the mash pH was in the proper range, perhaps polyphenols formed but precipitated out, yada yada yada. Point is, from what I've seen, and apparently also the pro brewers mentioned in the original post, chlorine in brewing water has not led to chlorophenols in the finished beer, even though the textbooks say it should. I honestly have no idea why. YMMV of course.

[dmtaylor]

That is called "luck".  I too was lucky for the first dozen or two batches.... until the one batch when I was unlucky and it was Band-Aid crazy and I had to research to find out how to prevent it.

[RC]

That is called "luck".  I too was lucky for the first dozen or two batches.... until the one batch when I was unlucky and it was Band-Aid crazy and I had to research to find out how to prevent it.

It seems exceedingly unlikely you would have gotten chlorophenol-free batches that many times simply as a matter of chance. Once or twice maybe, but a dozen or two batches? If I had that string of luck, I would quickly convince myself that luck had nothing to do with it.

The alternative? Perhaps there's more (or less) to the chemistry of chlorine-phenol interactions on the hot side than what we've all learned in the textbooks, and that the one batch of yours that had chlorophenols was probably infected.

I'm not arguing that these reactions don't occur. I'm merely stating the fact that, in a lot of brews, using unfiltered, chlorinated water has NOT resulted in chlorophenols in the finished beer. This has been my experience a few times, it has apparently been your experience a couple dozen times, it has been Brulosophy's experience at least twice (short and shoddy brews), and it is the experience of the pro brewers mentioned in this post.

If chlorine in brewing water is such a boogieman, these observations make no sense, especially given chlorophenol's extremely low taste threshold (~5 ppb, even less than diacetyl). Thus, it's within the realm of possibility to my pea-brain that our knowledge about these reactions is incomplete and/or not entirely accurate. (Of course, the same could be said about much of practical brewing chemistry.)

I'm talking only chlorine on the hot side. None of this applies to chloramines or to residual chlorine/bleach sanitizer left in a fermenter. I will also report that the tap water where I used to work had a level of chlorine in it that was tastable but very light. So it could be a matter of chlorine level vs. simply presence/absence.

[dmtaylor]

I had a friend at the time who worked for the municipal water department.  He said this is possible because in spring and fall they have to chlorinate more due to weather effects in the lake (I live on the big Lake Michigan which is our water source).  The beer I had with chlorophenol was brewed in like March or October.  Bingo.

[leejoreilly]

That is called "luck".  I too was lucky for the first dozen or two batches.... until the one batch when I was unlucky and it was Band-Aid crazy and I had to research to find out how to prevent it.

Those of us who are plagued with a engineering mind recognize "luck" as "probability in action", and I believe there's a lot of it in brewing. Just about every step in the process has some small chance of resulting in failure, and good (successful?) brewers do their best to minimize the worst of those chances.

There's some probability, say, of me getting away with poor sanitation procedures, and still producing pretty good beer. Until I hit that bad result, I can blithely claim that "Sanitation doesn't mean squat - I never clean my fermenter, and I haven't gotten an infection yet!" Of course, "yet" is the operable term - it's really only a matter of time until I do get an infection that exceeds my threshold of perception.

Same idea with stuff like adding campden tabs; assuming my water has chloramines (it does, by the way), I MIGHT be able to get away with not treating it for some number of batches before "luck" bites me on the butt. But bite me it will, eventually. This goes for lots of our brewing processes - water treatment, mash temp control, fermentation control, etc. You can certainly ignore the probabilities involved with sub-optimal procedures, but eventually you'll get bitten.

Some of the probabilities of failure are pretty big, and some are relatively tiny. And the solutions can range from dead simple easy, like adding a campden tab, to much more complex, like minimizing oxygen issues. Every brewer decides for him/herself which to address and which to ignore.

[a10t2]

I’m not arguing against the brewing chemistry written in textbooks. But I wish someone could explain this to me: Where I used to work, due to a (temporary) lack of QC we brewed three beers using unfiltered, chlorinated municipal tap water, not being aware that the carbon filter was broken. Not the faintest hint of chlorophenols in the finished beers. I infer that the pro brewers mentioned in the original post have had the same experience.

I'm wondering if there's still some chlorine/chloramine confusion going on in this thread. If the water supply uses chlorine *only*, then it will be driven off simply by heating to strike temperature (>70°C). As long as you aren't cold sparging the chlorinated water would never come into contact with the grain in the first place.

[RC]

I'm wondering if there's still some chlorine/chloramine confusion going on in this thread. If the water supply uses chlorine *only*, then it will be driven off simply by heating to strike temperature (>70°C). As long as you aren't cold sparging the chlorinated water would never come into contact with the grain in the first place.

This would explain the observations, but even so I didn't know chlorine gassed off that quickly--it doesn't take long to heat up 5 gal of 75-degree water to 165.

So, then, is the concern about using chlorinated tap water in brewing highly overblown? (Within reason, I mean. Perhaps there are times when chlorine levels are too high to gas off fully within the heating time, as Dave's experience suggests.)

Anyway, I'll test chlorine levels in straight-from-the-tap water before and after heating, using drinking-water chlorine test strips (it's the best I can do, plus it's good enough for me). The chlorine in my city's tap water varies between 1.0 and 1.1 ppm. It should go to zero after heating, right? If this happens, then I could simply use a test strip on my hose water, and if it reads below ~1ppm, skip the filtering!

[ynotbrusum]

I have tasted some Chicago homebrew where it could have used an extended time at strike temp, as the residual chlorine had not fully dissipated (it was at a barely perceptible level, but noticeable in a blond ale).  Now I routinely just suggest to new homebrewers a Campden tablet per 20 gallons of brewing water as insurance against chlorophenols.

Since I am on a well and run all of my brewing water through an RO system, I tend to overlook this chlorine issue when providing a recipe to new brewers, but it is just as important as fermentation temp control!

[Robert]

I'm wondering if there's still some chlorine/chloramine confusion going on in this thread. If the water supply uses chlorine *only*, then it will be driven off simply by heating to strike temperature (>70°C). As long as you aren't cold sparging the chlorinated water would never come into contact with the grain in the first place.

This would explain the observations, but even so I didn't know chlorine gassed off that quickly--it doesn't take long to heat up 5 gal of 75-degree water to 165.

So, then, is the concern about using chlorinated tap water in brewing highly overblown? (Within reason, I mean. Perhaps there are times when chlorine levels are too high to gas off fully within the heating time, as Dave's experience suggests.)

Anyway, I'll test chlorine levels in straight-from-the-tap water before and after heating, using drinking-water chlorine test strips (it's the best I can do, plus it's good enough for me). The chlorine in my city's tap water varies between 1.0 and 1.1 ppm. It should go to zero after heating, right? If this happens, then I could simply use a test strip on my hose water, and if it reads below ~1ppm, skip the filtering!

Chlorine will even gas off at room temperature if left uncovered long enough.  RC, while you're doing tests, how about adding an overnight cold stand for comparison?

One thing I'll add as a general caveat is that we don't necessarily know for sure what the water utility is doing.  Even where chlorine is the standard treatment,  they may resort to chloramine in occasional extraordinary circumstances.  Better safe than sorry.