Campden Tablets (Sulfites) and Brewing Water

[cervid]

Or, looked at another way, if your water has chloramine at 1 mg/L and you are treating 20 L you have 20 mg of chloramine to deal with requiring 20*3.127 mg metabite which is 20*3.127/20 mg/L.

Just looking at this now.. Doesn't that equation just come back to 3.127 mg/ml? That was an arbitrary equation in that, if I had 2 mg/ml of chloramine, then the ppm would double..

So.. couldn't I just take the mg of ions in either of those charts and multiply by a factor of whatever the mg/ml concentration of chlorine or chloramine is, respectively?

So, in your above example equation, I would be adding 2.70 mg/ml of SO4, when using the tablet in the prescribed amount we have been discussing? If my concentration of chloramine was 2 mg/ml, I would be adding 5.4 mg/ml of SO4, for instance?

Edit: I just heard back from my water guy regradring the municipal well. They chlorine where I am is between .2 and .5 ppm. Considering I will almost always be diluting my water, I'm not that worried about it.

 

[ajdelange]

Let's do an example which I hope will make it clear. Your water report says your water contains 2 mg chloramine per liter. You are preparing 40 L (about 10 gal) for brewing. The table says that each mg of chloramine requires 3.127 mg of K2S2O5 and produces 2.70 mg of sulfate and cancels 1.43/50 mEq of alkalinity. Thus for each liter of water treated you will need 2*3.127 = 6.254 mg of K2S2O5 per liter, will obtain 2*2.70 mg of sulfate per liter and remove 2*1.43/50 mEq alkalinity per liter equal to 2*1.43 ppm as CaCO3. Since you are working 'per liter' here the alkalinity can be written a 2*1.43 ppm as CaCO3. The total dose of metabite is, as you are treating 40 L 40*6.254 = 250 mg or about 1/2 a campden tablet.

Or you can multiply the 40 L by 2 mg/L to calculate that you must treat 80 mg chloramine. As each requires 3.127 you will need a total of 80*3.127 = 250 mg. Sulfate produced will be 80*2.70 mg. The mg/L, the number likely to be of more interest is 80*2.70/40 = 5.40 mg/L. 80 mg chloramine neutralizes 80*1.43 mg as CaCO3 alkalinity. Per liter that is 80*1.43/40 = 2*1.43 mg/L as CaCO3 (ppm as CaCO3). Thus it doesn't matter whether you prefer to work with total mg or mg/L. You get the same answer and well you should.

 

[BlitzkrausenNate]

Excellent info AJ.

I have been doing all grain for many years and have always bought bulk water from the grocery for a few dollars that claims to be chlorine/chloramine free. At my level much of this information is over my head at this point in the game anyway.

I know my local water supply has chorine/chloramine, would you suggest I find a printout of my municipal water supply and adjust with camden tablets as needed for the time be? Any other pointers? I appreciate your time and thanks in advance.

 

[ajdelange]

You can usually be guided by the results of the standing over night test. If you pass that then you don't need to do anything. If you don't then use half a tablet in 20 gallons of water treated. That will cover most situations. If you really want to be precise obtain a free and total chlorine kit from Hach or Lamotte or a pool supplier, measure the chlorine and chloramine and then use the tables to determine how much of a Campden tablet. Using too much campden won't hurt anything.

 

[BlitzkrausenNate]

Awesome, thanks!

 

[jmhbutler]

Okay, heres my question for one of you who's a chemistry wizz.

I have a 30L HLT but usually require about 35L for my all grain batches. I also add Potassium Metabisulphite at a rate of approximately 0.0666g/L.

If I were to fill my mash tun to the 25L mark, treat with K2S205, mash in, and then add 10L more of water [to my mash tun to use for sparging] **edit**...

- would the additional water have to be pretreated before being added to the HLT.

OR

- could the additional water be added and then the entire mixed water supply be treated with another hit of K2S205 proportionate to the amount of water added.

I think the latter is correct but have no solid grounds for my reasoning.

 

[mtnagel]

I think either way would be okay, but if you've already mashed in, I think you would be more likely to ensure the campden tablet is dissolved in if you added it to the second, separate water addition.

 

[jmhbutler]

Thanks Matt, I realize I wasn't clear. The additional water would be added to the water already in my hot liquor tank.

 

[Devin]

Possibly a stupid question, but I am not a chemist, so here goes: What effect will treating water with campden have on the ph of the water (and really, the ph of the mash, eventually)?

 

[ajdelange]

If you go back to #1 here you will see that for each mg/L chlorine neutralized by metabite 2.11/50 = 0.042 mEq/L of hydrogen ions are released while for each mg/L chloramine it is 0.028 mEq/L. These are not appreciable as they correspond to neutralization of water alkalinity of respectively 2.1 and 1.4 ppm as CaCO3 and a typical mash has buffering of 30 - 40 mEq/kg-pH.

 

[kal]

Possibly a stupid question, but I am not a chemist, so here goes: What effect will treating water with campden have on the ph of the water (and really, the ph of the mash, eventually)?

No effect that is noticed. You can ignore it.

Kal

 

[TheMadKing]

Sorry to bring this thread back from the dead, and maybe this has been covered somewhere, but several searches failed to find it.

Is there a way to account for the addition of metabisulfite in the Bru'n water spreadsheet? I'm probably not understanding the reactions well, but will Campden affect the addition of CaCl or gypsum?

 

[ajdelange]

Sorry to bring this thread back from the dead, and maybe this has been covered somewhere, but several searches failed to find it.

Is there a way to account for the addition of metabisulfite in the Bru'n water spreadsheet? I'm probably not understanding the reactions well, but will Campden affect the addition of CaCl or gypsum?

Have a look at the table in #1. It lists the things that potassium and sodium metabisulfite add to water in neutralizing chlorine and chloramine. Both chloride (from reduction of chlorine) and sulfate (from oxidation of sulfite) are added. Also note the release of some hydrogen ions (cancel alkalinity and lower pH). None of these effects should be noticeable.

 

[TheMadKing]

Have a look at the table in #1. It lists the things that potassium and sodium metabisulfite add to water in neutralizing chlorine and chloramine. Both chloride (from reduction of chlorine) and sulfate (from oxidation of sulfite) are added. Also note the release of some hydrogen ions (cancel alkalinity and lower pH). None of these effects should be noticeable.

I read it, and I guess my real question is: campden only reacts with free chlorine and chloramine ions and will not affect bound chlorine such as CaCl or NaCl correct?

And therefore it does not matter if I add the Campden before or after my CaCl/NaCl additions to my brewing water?

 

[ajdelange]

Metabite changes chlorine and chloramine to chloride and ammonia (chloramine only) and in so doing is converted to sulfate. As a consequence its use increases the concentration of all three of these ions (and H+ too) but no, it does not matter whether you add it before or after chloride and/or sulfate supplementation (to any appreciable extent).

 

[TheMadKing]

Thank you AJ, sorry if I was being dense as usual

 

[ajdelange]

Not a problem. If you remember redox from high school or college chem then all should be clear. If you don't or if you were never exposed then it wouldn't be so clear and asking for additional explanation is not unreasonable.

 

[TxBigHops]

good info. Thanks!

 

[JawZziff]

this thread should be a sticky. AJ, extremely informative.

 

[ajdelange]

If you came here via a link you would have no way of knowing it but it is indeed a sticky.

 

[JawZziff]

ah yes, I see now. subbed anyway for further reference.

 

[stlblues5010]

It takes an incredibly small amount of chlorine or chloramine to impart detectable chlorophenol in beer...even a recently washed serving glass that is still wet with chlorinated water will instantly create chlorophenol. Yes, in a finished beer!

The one time it occurred was in the Portland OR airport at a local brewery's bar. They had just washed the glasses in the typical glassware dunkings and served the beers in those glasses. I complained and thought that the beer was bad. They had apparently had this happen before since they dumped that beer and served the same beer in a properly rinsed and dried glass and there was no problem. Happy me.

So is this saying that every bar/brewery that water rinses their glasses prior to serving a drink is ruining the beer?

I'm just assuming, but I'm guessing most of them are using straight tap water when they are using the water sprayer.

 

[kal]

So is this saying that every bar/brewery that water rinses their glasses prior to serving a drink is ruining the beer?

I'm just assuming, but I'm guessing most of them are using straight tap water when they are using the water sprayer.

They are - I have a glass rinser in my bar and all bars would hook up to a standard cold water feed. That's how they're meant to be used. I find it hard to believe that a glass rinsed with tap water will cause issues with chloramine.

My city uses 2 ppm of chloramine which is fairly standard I would presume. I do remove it from my brewing water using the potassium metabisulphite but then do rinse my glass before pouring and have never noticed any issues.

Kal

 

[mabrungard]

That was a warning that this defect can arise from contact with chlorine compounds. Obviously, the actual concentration in your glass is dependent upon the amount of residual water in your glass and the concentration of chlorine compounds in that water. The problem is most acute when the glasses came out of a chlorine-based cleaning solution. A rinse with the typical tap water may not have enough chlorine compounds in it to affect taste. But it might!

 

[ajdelange]

Way back in #54 I described an experiment in which beer was dosed with chlorine to the extent of 5 ppm and no chlorphenolics were detected even after allowing the beer to stand. I'm not saying there isn't a way to screw things up with improper rinsing but given that a glass rinsed with water tap water at 3 ppm chlorine/chloramine is going to introduce a level in beer subsequently introduced into that glass much much less than 3 ppm (30 ppb?) and that beer dosed to 5 ppm doesn't suffer detriment it is unlikely that beer served in a glass rinsed with tap water will.