Campden tablet after adding star san?.

[danio]

Hello all - I've recently started to wonder if my RO water from a grocery store dispenser actually has chlorine and\or chloramine in it! A bunch of kind folks in the AG forum helped me troubleshoot a medicinal flavor my last few batches. I switched to RO and the taste is greatly diminished but still there (I'm also going to monitor pH carefully, in case it's due to that and just a change in pH).

Long story short, I have a bunch of water mixed up that is RO + star san. Can I add a campden tablet to that sanitizer water to drop out chloramine etc or will it mess up the star san? I wouldn't want the water I rinse my carboy with right at the end to be what introduces my chloramine taste (a tip I found in this thread.) I'll obviously be adding campden to my RO sparge\strike water. I guess I'll do this prior to adding CaCl and CaS04.

I just hate to pour out 5 gallons of primo san star RO water that is still crystal clear, I just wasn't sure if campden tablets have to come first or something.

Thanks!

Dan

 

[ehedge20]

Does the water get run thru a carbon filter to remove the Chlorine / Chloramine? I use two in line filters from the depot and they do a really good job.

 

[danio]

Well it's just at Winco. So I don't know how good a job they do. I'm just running out of things that could cause this flavor. Maybe I should try a chlorine kit.

 

[ajdelange]

The RO water won't contain any chloramine or chlorine unless there was a failure of the membrane and the carbon filter which precedes it. The carbon filter is there, in part, to protect the filter from chlorine/chloramine so I suppose if it became exhausted the membrane might fail soon after allowing one or the other or both into the finished water but that would be only in the case of a broken machine.

If there is enough chlorine or chloramine in water to be a problem you can smell it upon pouring the water back and forth between 2 tumblers.

 

[DSmith]

I'd start over with your sanitizer and dechlorinate your tap water first. It's probably going to be the only sanitizer batch you dump if you keep dechlorinating your water first from now on.

I've been dechlorinating all my washing (PBW) and santizing (Star San) water prior to adding the detergent / sanitizer for both brewing and bottling. It really makes no sense to dechlorinate the PBW water because I rinse with chlorinated tap water... These are 3 gallon batches of water and throwing out the majority of the campden tablet seems pretty wasteful when you can dechlorinate something else. A campden tablet weighs about 0.65 grams, so I use 0.10 grams for each 3 gallons of water and throw the rest out, or use it to dechlorinate brewing water at the same time.

 

[danio]

AJ - Yeah, I thought it might just be a broken machine...? Considering my off flavor decreased but didn't disappear I figured it had to do with quantity of 'something.' Which made me think of chloramine, etc. Granted my pH also probably diminished now that I'm using RO (I JUST got precision strips and am looking for a good meter so I'll soon know real pH). The really weird thing is I get the EXACT flavor from Ninkasi Total Domination IPA but just infinitesimally small. Barely perceptible and I only notice it because I have many times that quantity of taste from my recent IPAs.

DSmith - I'll probably take your advice and just re-start. I would use my tap water but the pH is 8.3 so my star san immediately goes cloudy. I just hate going to Winco

 

[mabrungard]

There are RO membranes that can tolerate chlorine, but they are rare. More than likely, the vending machine RO is free of chlorine compounds. If you are going to buy your water from one of those machines, get a TDS meter to check the quality of the water you buy. The meter should be less than $30. You should see less than 20 ppm TDS from a properly operating machine.

 

[ehedge20]

AJ - Yeah, I thought it might just be a broken machine...? Considering my off flavor decreased but didn't disappear I figured it had to do with quantity of 'something.' Which made me think of chloramine, etc. Granted my pH also probably diminished now that I'm using RO (I JUST got precision strips and am looking for a good meter so I'll soon know real pH). The really weird thing is I get the EXACT flavor from Ninkasi Total Domination IPA but just infinitesimally small. Barely perceptible and I only notice it because I have many times that quantity of taste from my recent IPAs.

DSmith - I'll probably take your advice and just re-start. I would use my tap water but the pH is 8.3 so my star san immediately goes cloudy. I just hate going to Winco

I would invest in the inline carbon filters as they are cheap and you can use your tap water. I run my water thru slowly to make sure I have it all out. As far as your PH my water runs at 7 and I just use a little more StarSan and let it sit for a little longer (2 min) and have never had a problem.

 

[DaleHair]

I believe citric acid and ascorbic acid will remove chloramine, will phosphoric acid, main ingredient in starsan also remove it.

 

[ajdelange]

Ascorbic acid is well known as a reducing agent (antioxidant) and will reduce chloramine (though I've never tried it). Citric acid, AFAIK, is not and therefore won't. Same for phosphoric.

 

[mabrungard]

Citric will remove hypochlorite, I'm not sure about chloramine. Citric acid was proposed as the dechlorinating agent for Great Lakes ship bilge water after it is chlorinated to stop the infections to the lakes as happened with the Zebra Mussels.

 

[danio]

Would there be any advantage to using acids instead of campden?

Also, I thought inline charcoal didn't take care of chloramine? Or does it?

It sounds like RO water having chloramine\chlorine is pretty unlikely. I was just brainstorming. It's probably my pH then. It's only with AG and the batches that taste ok either have mash hops or a few lb of dark malt. The ones that taste bad are almost all 2-row.

 

[ajdelange]

Citric will remove hypochlorite, I'm not sure about chloramine. Citric acid was proposed as the dechlorinating agent for Great Lakes ship bilge water after it is chlorinated to stop the infections to the lakes as happened with the Zebra Mussels.

With chlorine it's an acid-base reaction. When chlorine is dissolved in water
Cl2 + H2O <---> H+ + Cl- + HOCl
Acidifying chlorinated water pushes the reaction (Le Chatelier) to the left releasing the chlorine. Many a housewife has learned the hard way not to mix vinegar with bleach.

Acid won't work with chloramine unless it is a reducing acid (which ascorbic and sulfurous acids are). Electrons are required:
NH2Cl + 2H+ + 2e- ---> NH4+ + Cl-
If sulfur dioxide (forms sulfurous acid when dissolved in water)is used to supply the electrons
SO2 + 2(OH-) --> SO4-2 + 2H+ + 2e-
For an overall reaction
NH2Cl + SO2 ---> SO4-2 + NH4+ + Cl- + 2H+

Note that metabite is "solid SO2": S2O5- + H2O ---> 2SO2 + 2(OH-)

Would there be any advantage to using acids instead of campden?

No. Campden is pretty much ideal as the oxidized product is sulfate ion which, in modest quantities, is not detrimental to the most delicate beers and in some beers is wanted in much larger amounts than result from oxidation of SO2 by chloramine. If another reducing agent, such as ascorbic acid, is used then the beer will contain oxidized ascorbic acid. In the small quantities produced this would probably not have a detrimental effect but sulfate is sort of the devil we know.

The ammonium ion and chloride, both of which are beneficial to beer, the former as a yeast nutrient and the latter as a body enhancer, are the products of reduced chloramine and will be present whichever reducing agent is used.

 

[ehedge20]

Charcoal filters will remove chloromines but you have to do it slow. It take me about 6 hours to filter my water so I set it up the night before and run until I have more than enough. I also hook two pots togeather so I am sure I will not have any overflow.

 

[ajdelange]

As noted in #4 all RO systems (or all the ones I have ever seen) have a charcoal filter one of whose functions is to protect the membrane(s) by removing chlorine and chloramine from the feed water. One of the interesting aspects of the activated carbon chemistry is that carbon sites are initially oxidized by some of the chloramine but then those sites are reduced by additional chloramine so that the overall reaction is
3NH2Cl --> 2H+ + 3Cl- + NH4+ + N2
i.e. as with chemical reduction the chloramine is reduced to chloride and ammonium but the oxidized product is nitrogen gas. What's interesting is that, theoretically, the carbon is not consumed. With chlorine, however, it is
C* + OCl- ---> C*O + Cl-
(C* represents an active carbon site and C*O an oxidized active carbon site).

 

[danio]

Ok, thanks for the data AJ and Ehedge. I will probably get a TDS meter to see what my store bought RO is like. I will also smell for chlorine today. I'm just suspicious of a machine that probably is under very little scrutiny as far as whether it's 100% effective. I'm trying to get my hands on a pH meter too, although I just got some precision strips.

 

[GodsStepBrother]

You can also go to your local pool supply store and they have strips that will show you if your water has chlorine in it. They are five bucks, and though not the most accurate things in the world, they will show you if there is some present. I use them to make sure my filter is still doing a good job. Just soak one with normal tap water see the color then soak the other one in your brewing water.