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General Category => All Grain Brewing => Topic started by: tygo on February 22, 2010, 03:31:37 AM

Title: Campden Addtions
Post by: tygo on February 22, 2010, 03:31:37 AM
When you add a campden tablet to water to eliminate the chloramine what are you adding to the water on a net basis?  Just looking around on the web it looks like adding one campden tablet to 10 gallons of water would add 6.7 ppm sulfur dioxide but that supposedly goes away as it reacts with chlorine and chloramine.  So does that mean that the addition of the tablet adds nothing on a net basis or are there some residual mineral additions that should be taken into account when building your water?

I know that the common convention is that one tablet should be added to 20 gallons of water.  Is there enough of an impact that only half a tablet should be added to 10 gallons? 
Title: Re: Campden Addtions
Post by: BrewArk on February 22, 2010, 05:55:01 PM
Municipal water with chloramine added will be above neutral pH, w/mostly monochloramine.  Added sulfur dioxide combines w/water to form some sulfurous acid that reacts w/monochoramine to produce ammonium, chloride, hydrogen, and sulfate ions in your solution.

SO2 + H2O --> H2SO3,

H2SO3 + NH2Cl + H2O --> NH4+ + Cl- + 2H+ + SO4-

Drinking water is supposed to be less than 4 ppm chloramine, so it looks like you are in the ballpark.
Title: Re: Campden Addtions
Post by: Jeff Renner on February 23, 2010, 01:52:32 PM
Extra SO2 won't hurt, and I add some potassium metabisulfite powder (cheaper than campden tabs) to my mash as insurance against oxidation.  It's volatile and is gone by the end of the boil.  Some yeasts, especially lager yeasts, produce SO2, which helps against oxidation in the same way.
Title: Re: Campden Addtions
Post by: denny on February 23, 2010, 05:05:57 PM
Extra SO2 won't hurt, and I add some potassium metabisulfite powder (cheaper than campden tabs) to my mash as insurance against oxidation.  It's volatile and is gone by the end of the boil.  Some yeasts, especially lager yeasts, produce SO2, which helps against oxidation in the same way.

Jeff, have you noticed any difference doing that?  I experimented with it fir a year and eventually stopped because I couldn't tell if it was doing anything.  Maybe I wasn't getting enough oxidation to worry about in the first place?
Title: Re: Campden Addtions
Post by: tygo on February 23, 2010, 05:09:52 PM
Thanks for the responses.  I'm going to relax and not worry about this, which I figured was the answer but I wanted to confirm.
Title: Re: Campden Addtions
Post by: tom on February 23, 2010, 05:10:39 PM
What is the recommended dose to prevent oxidation? I seem to remember 25 ppm, but it is pretty hazy.
Title: Re: Campden Addtions
Post by: denny on February 23, 2010, 05:17:06 PM
What is the recommended dose to prevent oxidation? I seem to remember 25 ppm, but it is pretty hazy.

Hazy here, too, Tom.  I recall I'd use either 1/2 or 1 tab in a mash for a 5 gal. batch, but I don't recall what concentration it was.
Title: Re: Campden Addtions
Post by: Jeff Renner on February 23, 2010, 06:13:38 PM
Denny - I can't say I've noticed any difference, probably for the same reason that you gave, but it's cheap insurance.  I don't always remember to do it.

I don't know the correct dosage, either, but I use about 1/4 tsp in a ten gallon batch.
Title: Re: Campden Addtions
Post by: denny on February 23, 2010, 08:12:03 PM
Jeff, I'm a big fan of cheap insurance!
Title: Re: Campden Addtions
Post by: ndcube on February 23, 2010, 09:25:49 PM
How gentle are you guys with your mash (or not gentle).

I'm usually pretty careful but on my first decoction, not so much.  I'll have to see if there is any difference as far as oxidation.
Title: Re: Campden Addtions
Post by: denny on February 23, 2010, 10:03:08 PM
Not too gentle.  I pour in water and stir vigorously. 
Title: Re: Campden Addtions
Post by: Jeff Renner on February 23, 2010, 11:17:26 PM
I pour in water and stir, but I'm careful not to incorporate air.  Same when I do a decoction - I'm careful not to splash more than a minimum.
Title: Re: Campden Addtions
Post by: ndcube on February 24, 2010, 12:00:59 AM
So you think the mash can oxidize in the time it takes to mash?  I would think that the O2 absorbed by any splashing would be driven off in the boil but that's just a WAG.
Title: Re: Campden Addtions
Post by: Jeff Renner on February 24, 2010, 12:12:52 AM
This has been a hot and controversial topic over the years among homebrewers.  It has its own acronym, HSA, for hot side aeration.  In theory, at least, if the wort components are oxidized in the mash or any time before chilling, they won't get unoxidized (reduced) later, although the problem may not show up immediately.

If you are a masochist, do a google hbd.org site search for hsa and stand back!
Title: Re: Campden Addtions
Post by: ndcube on February 24, 2010, 12:21:17 AM
Don't worry.  I've been there but it's been so long I don't remember most of what I googled.  I just always try to be as careful as possible in case HSA exists.  Just have to get my decoction process down.
Title: Re: Campden Addtions
Post by: mariojr on March 03, 2010, 03:47:34 PM
Sorry to hijack this thread, but I have a question about Campden too.  In an attempt to save a little time I'd like to start heating my mash/sparge water while it's filtering into my HLT.  Can I add the Campden to the heated water and still have it work? or should I just have a second cup of coffee during the few extra minutes I'll add by waiting to heat the full amount of water?

Thanks.

MArio
Title: Re: Campden Addtions
Post by: Jeff Renner on March 03, 2010, 03:52:10 PM
I think that adding it to warm or hot water would work fine, but you'd probably want to stir it immediately so distribute it before it all volatilizes.