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martinworswick 01-07-2010 03:09 AM

campden tablets and its effect on base water levels
 
i understand that if you add a campden tablet to remove chloramine (correct me if i'm wrong here) then the campden reacts with the chloramine and it dissipates out into calcium,bicarbonate and water.

are the amounts of calcium and bicarbonates significant enough to worry about? how much would it adjust your base water levels? do you need to take these into account when adding further salts to your water?

your wisdom is appreciated!

cheers
martin
:mug:

jpc 01-07-2010 05:05 AM

I see one problem with this... there is no Cl in the "equation".

That said, I have the same question... what does it add to the base water?

johnnyc 01-07-2010 12:33 PM

Quote:

Chapter 4 - Water for Extract Brewing
4.1 Home Water Treatment

If the water smells bad, many odors (including chlorine) can be removed by boiling. Some city water supplies use a chemical called chloramine instead of chlorine to kill bacteria. Chloramine cannot be removed by boiling and will give a medicinal taste to beer. Chloramine can be removed by running the water through an activated-charcoal filter, or by adding a campden tablet (potassium metabisulfite). Charcoal filters are a good way to remove most odors and bad tastes due to dissolved gases and organic substances. These filters are relatively inexpensive and can be attached inline to the faucet or spigot. Campden tablets are used in winemaking and should be available at your homebrew supply shop. One tablet will treat 20 gallons, so use only a quarter or half of the tablet to help it dissolve. Another alternative is to use bottled water from the grocery store.

If the water has a metallic taste or leaves hard deposits on the plumbing, then aeration, boiling, and letting it cool overnight will precipitate the excess minerals. Pour the water off into another pot to leave the minerals behind. Water softening systems can also be used to remove bad-tasting minerals like iron, copper, and manganese as well as the scale-causing minerals, calcium and magnesium. Salt-based water softeners use ion exchange to replace these heavier metals with sodium. Softened water works fine for extract brewing but should be used with caution for all-grain brewing. Depending on the type of beer, the mashing process requires a particular balance of minerals in the water that the softening process will remove.

A good bet for your first batch of beer is the bottled water sold in most supermarkets as drinking water. Use the 2.5 gallon containers. Use one container for boiling the extract and set the other aside for addition to the fermenter later.
From Palmer on Campden tablets.

martinworswick 01-07-2010 07:45 PM

brew-monkey is where i read the original information-

Quote:

Chlorine can be eliminated in simple ways, such as simply letting it gas out of the water over time (usually overnight) or by pre-boiling the mash water. Chloramines are not as easily degraded. Chloramines will breakdown with the use of campden tablets, which will break the chloramines into calcium, water and bicarbonate. Failure to deal with chlorine or chloramines can result in yeast metabolizing these into harsh medicinal notes called chlorophenols. This is also true of using too much chlorine as a sanitizer.
a bit more digging around suggests chloride and sulfates are precipitated out but i don't seem to be able to find a definitive answer as to how much and if it contributes anything significant to the original water profile?

martinworswick 01-07-2010 10:56 PM

it turns out this is all academic for me as i emailed the local council to find out about our water supply treatment and received this reply

Quote:

Good Morning Martin,

Thank you for your email enquiry below regarding water treatment in Arrowtown.
I can confirm that currently there is no water treatment process in place in Arrowtown. It is abstracted directly from the bore and pumped into the reservoirs where it gravitates to the town supply reticulation.

I hope this helps with producing wonderful, local beer!


Regards

Zuz
:mug:

Rushis 01-07-2010 11:06 PM

Quote:

Chloramines will breakdown with the use of campden tablets, which will break the chloramines into calcium, water and bicarbonate.
Not really ;)

I wrote out some equations for the reactions of sodium metabisulfite in water with chloroamine in this thread. You should get chloride, ammonia, and sulfate.


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