Is potassium metabisulphite the same as campden?

BroomVikin · Apr 22, 2016

So to start I'd like to say I know ZERO about water chemistry. I'm told that the water in my area (NW Atlanta) is generally pretty good as is and doesn't need a lot of help. That being said I've generally picked up from the forums that ½ a campden tablet or so can't hurt anything and might do some good even for a decent municipal water report. So, that in mind, I decided during my latest trip to the LHBS "What the heck? It can't hurt." Unfortunately, upon arriving home and unloading my bag o'goodies I discovered that I had been sold potassium metabisulfite. Even worse it is in powder form! So here's my question, is this stuff the same as the mythical campden tablet? Is it a comparable substitute? Also, assuming it is, how much should I use for a typical 5g batch? Thanks for the collective knowledge. When it comes to this stuff I've got absolutely none!

lumpher · Apr 22, 2016

Yes, it is. Campden tablets are Potassium Metabisulfite, and I'd use about 1/2 a teaspoon to help neutralize chloramines.

GilaMinumBeer · Apr 22, 2016

It is essentially the same. Campden is technically Sodium Met but, they both have the same end result.

I actually prefer powdered. The tablets actually need to be crushed before adding to aid in dissolving.

1/8th to 1/4 teaspoon per 5 gallons, for chlorine/chloramine removal.

ColdbreakBrewing · Apr 22, 2016

BroomVikin said:
So to start I'd like to say I know ZERO about water chemistry. I'm told that the water in my area (NW Atlanta) is generally pretty good as is and doesn't need a lot of help. That being said I've generally picked up from the forums that ½ a campden tablet or so can't hurt anything and might do some good even for a decent municipal water report. So, that in mind, I decided during my latest trip to the LHBS "What the heck? It can't hurt." Unfortunately, upon arriving home and unloading my bag o'goodies I discovered that I had been sold potassium metabisulfite. Even worse it is in powder form! So here's my question, is this stuff the same as the mythical campden tablet? Is it a comparable substitute? Also, assuming it is, how much should I use for a typical 5g batch? Thanks for the collective knowledge. When it comes to this stuff I've got absolutely none!

Campden tablets are either potassium metabisulphite or sodium metabisulphite. You have the exact same thing, only in powdered form. 1 tablet is 550mg. So you can just weigh it out.