Removing Chlorine

[Travisty]

Campden tablets may harm the yeast if you were to add them to your wort prior to or after pitching and added them in a quantity of about 1 tablet per gallon or so, but adding them to your mash and sparge water will not harm your yeast one bit. The sulfur dioxide created (the stuff that acts as a preservative) is pretty volatile and will be driven off by heating the treated water. It's volatile enough that winemakers have to keep dosing their wine with sulfites to maintain a certain level up until they bottle.

The reaction that removes the chlorine/chloramines happens nearly immediately.

I've thought about getting a filter to remove the chloramines in my water, but after I realized that you have to run your water through at a slowish rate I decided against it. With campden tablets I can fill my HLT and mash tun as fast as my faucet and RV hose will flow, toss a crushed campden tablet in each vessel and be done. Cheap, fast, and easy!

[KimJongAle]

I had been using Campden tablets regularly up until recently. I was told a.) your charcoal filter will eliminate chloramine and b.) Campden tablets can harm yeast if not let to sit for a considerable amount of time. I had always filtered my water, then dumped in a proportion of a crushed Campden tablet for the amount of water I was using to mash & sparge, then began to heat my water. I didn't let the water sit at all. So, was I mislead?

To expand a little on what Travisty said, a carbon filter can remove chloramine from water. However, the problem is the extended contact time required with the filter medium. I don't recall the exact rate they cited on the Brew Strong episode...but is a rate of several minutes per gallon. On top of that, Palmer has said that a carbon filter will only remove 80-90% of the chlorine. This my reasoning for stating previously that (generally) it is ineffective for home brewers to use carbon filtration to remove chloramine.

Campden is your best defense against chloramine, and is quite safe for the yeast in the quantities used for de-chlorination.

[Rhoobarb]

Okay, you have sold me. I'm going back to what I did before. Thanks for the info and clarification!

[ajdelange]

The products of the reaction between chloramine and bisulfite are ammonium ion, chloride ion and sulfate ion. If there is excess bisulfite then there will be sulfur dioxide as well. Sulfur dioxide is a pretty powerful reducing agent and will not harm yeast (although it is effective against wild yeast). It just reduces something in the wort. I know brewers who add it to the kettle not to combat chloramine but just for this reducing effect. They claim, among other things, that it results in a lighter colored beer. Besides that the boil will drive any sulfur dioxide that does not reduce something off. Sulfate is harmless to yeast and the ammonia is actually beneficial to them. Many of the yeast nutrients are a mixture of urea (which breaks down into ammonia and CO2) and ammonium phosphate.

GAC is effective against chloramine but it does take contact time. RO units are poisoned by chlorine and chloramine and use a GAC filter to protect the membrane. As I noted in an earlier post, if you can't smell chlorine in a sample of the brewing water, i.e. if you have run it through a GAC filter and don't smell the stuff, you are probably safe.

[ChristianSA]

Campden tablets may harm the yeast if you were to add them to your wort prior to or after pitching and added them in a quantity of about 1 tablet per gallon or so, but adding them to your mash and sparge water will not harm your yeast one bit. The sulfur dioxide created (the stuff that acts as a preservative) is pretty volatile and will be driven off by heating the treated water. It's volatile enough that winemakers have to keep dosing their wine with sulfites to maintain a certain level up until they bottle.

The reaction that removes the chlorine/chloramines happens nearly immediately.

I've thought about getting a filter to remove the chloramines in my water, but after I realized that you have to run your water through at a slowish rate I decided against it. With campden tablets I can fill my HLT and mash tun as fast as my faucet and RV hose will flow, toss a crushed campden tablet in each vessel and be done. Cheap, fast, and easy!

I went out at got some Campden tablet. They are tiny and I only need to dechlorinate 25 liters at a time. One tablet is enough for 100L so measuring a quarter if a tablet with any accuracy is almost impossible.

Can I crush one tablet, dissolve it in water and dose part of that water into my brewing liqour?

Can I store the solution if it is done in an airtight container?

-Christian

[ajdelange]

Can I crush one tablet, dissolve it in water and dose part of that water into my brewing liqour?

Yes, that's a good idea as it is a bit tricky to get the stuff to dissolve completely. Put it in a glass, crush with the back of a spoon, add water, stir and add just enough of the liquid to kill the chlorine smell. When you smell sulfur dioxide more than chlorine you are finished.

Can I store the solution if it is done in an airtight container?

Probably, but why bother?

[Travisty]

I don't know that I would go through the trouble of only dosing your water with part of a tablet. AFAIK adding 1 tablet to 25L of water isn't going to hurt anything and the tablets are cheap.

[ajdelange]

1 tablet is enough to process 20 gallons (about 76 L) so if you put one tablet in 25 L you are dosing with triple the needed amount. In fact, the 20 gallon capacity of a single tablet is for the situation where the treatment plant has dosed to the extent of 3 mg/L (the max allowed) which is more than most do (total chlorine may be 3 mg/L but chloramine is usually half to a third of this). So in most cases it only takes part of a tablet to do 76L. While it's true that even 6 times the required dose doesn't put that much into the water some people don't like anything more than what they have planned for. Why use more than you have to? Possible answer: you want the reducing power of the unused bisulfite.

With a little experience you should be able to determine how much of a tablet is required to treat the volume of water you treat and can use just that much (e.g. 1/4 tablet) next time. If your municipality boosts the chlorination in the spring (as many do) you can rely on the smell test. If you can't smell it, you've defeated chloramine.