Any ideas what campden tablets are made of and how much to use to treat 9.25 gallons

If we wanna treat the water to get Cl our of it....we need to use campden tablets. I understand that part, but instead of buying the tablets from a LHS, I thought I'd look up what they are made of and wikipedia says that they are made of sodium metabisulfite -Na2S2O5 or potassium metabisulfite -K2S2O5.

Now........which one are they? Because I could locally buy either of these from a chemist and use them to treat the water, but I also have to figure out how much I should per 9.25 gallons of mashing water.....I have no idea about that. Any advice on these matters?

UPDATE: I can calculate the molecular weight of the above mentioned chemicals....but I need to know the dose of campden tablets per gallon then and their chemical composition. Can anyone give me that? I'd really appreciate it.

That all depends on the brand you are using.

You should be able to get either of those chemicals from a LHBS or online. Check in the wine additives section.

If you are using E.C. Kraus products, then use 1/8 tsp K-meta to replace one Campden Tablet.

http://www.eckraus.com/8-oz-potassium-metabisulfite.html

I know the bag of campden's I have say to use 1 tablet per 5 gallons......

They can be either sodium or potassium, I don't think it would matter either way. It's the metabisulfite that does the neutralizing.

One tablet is good for 20 gallons when you're just using it to dechlorinate. Looking at a few labels a tablet is about 550 mg of the potassium metabisulfite.

Felixio said:

That all depends on the brand you are using.

You should be able to get either of those chemicals from a LHBS or online. Check in the wine additives section.

If you are using E.C. Kraus products, then use 1/8 tsp K-meta to replace one Campden Tablet.

http://www.eckraus.com/8-oz-potassium-metabisulfite.html

Click to expand...

Thanks for the reply.
That's exactly what I was saying....."I can get them locally".....I am not looking for brands...because these chemicals are available here from a little store I know. No brand name....nothing...it is 100% sodium metabisulfite -Na2S2O5 or potassium metabisulfite -K2S2O5, but I need to know how much to use....

We have established them either of them are okay....now, I gotta work out how much I need to use.

Elysium said:

Thanks for the reply.
That's exactly what I was saying....."I can get them locally".....I am not looking for brands...because these chemicals are available here from a little store I know. No brand name....nothing...it is 100% sodium metabisulfite -Na2S2O5 or potassium metabisulfite -K2S2O5, but I need to know how much to use....

We have established them either of them are okay....now, I gotta work out how much I need to use.

Click to expand...

Since you're only treating the water for chlorine, the typical treatment would be 1 tablet (1/8 tsp) per 20 gallons. I would just round your water volume to 10 gallons and call it half of a campden tablet or 1/16 tsp. You could either use a pill cutter from the local drug store, or a micro scale to figure out how many g/mg are in a set measurement of k-meta and divide that appropriately. (i.e. Measure 1/4 tsp and divide by 4.)