[denny]

Martin, roughly how much sulfate from one tablet would need to be accounted for in Bru'nwater (or other) ?  There is another thread currently that discusses using a campden tablet in the mash as a source of antioxidant against staling of malt compounds.

The tabs are sufite, so I'm not sure there would be any sulfate to account for at all.

[HoosierBrew]

IIRC one campden tablet will dechlorinate 20 gallons of water.  In other words, 1/4 tab per 5 gallons. Crush it, stir it in, let it sit overnight and you should be good.

Ah ok...so I can't add it during the brewing process?

I've used all RO forever (tap water is crap here), but my understanding is that you need to the day before to give it time to off gas the chlorine and/or chloramines.

Actually, it works in just a few seconds.  But you do need to add it before you start. 

Thanks, Denny.  Long time RO user here. I had it in my head that the water had to sit overnight.

[HoosierBrew]

Martin, roughly how much sulfate from one tablet would need to be accounted for in Bru'nwater (or other) ?  There is another thread currently that discusses using a campden tablet in the mash as a source of antioxidant against staling of malt compounds.

The tabs are sufite, so I'm not sure there would be any sulfate to account for at all.

I thought Martin had posted that the sulfite gets downgraded to sulfate by the boil.

[denny]

I thought Martin had posted that the sulfite gets downgraded to sulfate by the boil.

It might.  It's just a difference of one oxygen molecule.

[a10t2]

Martin, roughly how much sulfate from one tablet would need to be accounted for in Bru'nwater (or other) ?

The packaging says one tablet/gal is "150 ppm", but not of what. So at one tablet per 20 gal, ~8 ppm of something or other. Probably SO₂ since that's what a vintner would actually be worried about.

My tablets mass ~650 mg. If you assume that's entirely K₂S₂O₅ - I'm sure there's also some sort of binder, but we'll establish an upper bound - that's 5.6 ppm of metabisufite, or 3.7 ppm of sulfate assuming my stoichiometry checks out.

[HoosierBrew]

Martin, roughly how much sulfate from one tablet would need to be accounted for in Bru'nwater (or other) ?

The packaging says one tablet/gal is "150 ppm", but not of what. So at one tablet per 20 gal, ~8 ppm of something or other. Probably SO₂ since that's what a vintner would actually be worried about.

My tablets mass ~650 mg. If you assume that's entirely K₂S₂O₅ - I'm sure there's also some sort of binder, but we'll establish an upper bound - that's 5.6 ppm of metabisufite, or 3.7 ppm of sulfate assuming my stoichiometry checks out.

Sounds pretty negligible anyway. Thanks for the info !