So They Are Magic?!

[Garrete]

I was reading about capden tablets all over The Net. So do the chloramines drop out of solution and fall to the bottom of the container, making it necessary to rack the water off or can we just dump the whole thing in our mash tun?

Also, does the temp of the water matter for the tabs working?

Thank you in advance.

[ajdelange]

Not just magic, "FM"!

I was reading about capden tablets all over The Net. So do the chloramines drop out of solution and fall to the bottom of the container, making it necessary to rack the water off or can we just dump the whole thing in our mash tun?

Campden tablets are usually potassium bisulfite (but they can be sodium bisulfite). Assuming potassium the reaction is K2S2O5 + 2NH2Cl + 3H2O --> 2SO4-- + 2H+ + 2Cl- + 2NH4+ + 2K+ thus the chloramine is reduced to ammonium ion and chloride ion while the bisulfite is oxidized to sulfate. The potassium ion stays in solution as well. As very little potassium bisulfite is added (1 tablet usually will treat 20 gallons) very little of any of these products are released into the treated water and ammonium (yeast nutrient) and chloride are generally considered beneficial anyway. Just to be 100% clear: everything stays in solution - there is no need to rack. The Campden tablets themselves can be difficult to dissolve. I recommend crushing them with a spoon back to a fine powder and then adding the powder. You may see granules of undissolved bisulfite in the water but these will eventually dissolve. It will probably not be necessary that they be completely dissolved in order for them to remove all the chloramine in a typical water.

Also, does the temp of the water matter for the tabs working?

Temperature always matters but as the rate constant for this reaction is so high it doesn't matter very much whether the water is icy cold or just at room temperature. It's easy to tell when the reaction is complete: you can't smell chlorine any more though you may be able to smell sulfur dioxide (don't worry about this - it will either be driven off by the heat of the mash/boil or, and this is what you hope for, reduce something in the mash/wort). Those who want stronger proof can obtain a chlorine/chloramine test kit from an aquarist's supply house (or other source).

[Chupa LaHomebrew]

And, as a slightly less scientific, but experience based assessment of campden tablets in water, I use them all the time and they work great. I crush them with a mortar and pestle. Totally gets rid of the "swimming pool" smell of my water as it is heating up, and helps me relax and not worry about chlorophenols in my beer.

[Cutt]

Chupa, let me get this straight:
So you relax, don't worry about chlorophenols in you beer, and have a non-swimming pool homebrew? Papazian would be proud.

I, on the other hand, filled up my brew kettle yesterday with about 7 gallons of swimming pool. To be fair the initial chlorine smell went away prior to filling my kettle, but I still get anxious until kegging time. I guess I need to get some of those magic pills. Thanks for the info.

[ajdelange]

Your nose is actually a pretty good chlorine/chloramine detecter. I you can't smell chlorine, especially when the water is poured back and forth between a couple of glasses, you don't have enough chlorine or chloramine to worry about and don't need Campden tablets.

[Chupa LaHomebrew]

Portland Oregon water does not have a strong chlorine smell, it's great water, but you notice it if you heat up a large volume. I am, I would say, slightly more anal in my brewing habits than Charlie, although he was my first teacher. I had to unlearn a lot of that stuff later on.

[brewinhard]

I would say that most public tap water probably has at least a minimal aroma of chlorine in it not good for brewing with. With that being said, I have never used campden tablets. I simply draw my water 24-48 hrs in advance and let it sit out with a lid partially on to let the gases escape. Seems to work just fine at least in Western NY.

[Travisty]

I would say that most public tap water probably has at least a minimal aroma of chlorine in it not good for brewing with. With that being said, I have never used campden tablets. I simply draw my water 24-48 hrs in advance and let it sit out with a lid partially on to let the gases escape. Seems to work just fine at least in Western NY.

That won't work for chloramines though and I've heard that most municipal water supplies have chloramines rather than chlorine these days. I know our water does which is why I use campden tabs in my water.