Calling all Chemists ~ Using old Pot Meta for Chloramine Removal

I currently use  potassium metabisulfite .035g per gallon of water for Chloramine removal for my brewing water.

I am looking for information regarding use of old pot meta for the same thing.

I usually buy more pot meta than I use in a year for wines, and meads. The general rule is to get
fresh pot meta ever year or it may not work, but it is still good for cleaning equipment.

So my question…Is it still good for Chloramine removal as well?
Any Chemists out there with the answer?

I am a chemical engineer, not that I think this qualifies me to answer your question any more than anyone else.  But…

Yeah, the old stuff will work just fine for chloramine removal.  Perfect use for it.  I don’t know how many grams are in a tablet, but based on things I have read, you need roughly 1/8 tablet per 5-6 gallons of water.

Shoot… I bought my Campden tablets roughly 7 years ago, and I still have almost a full bottle and still use them today.  I haven’t had one single Band-Aid flavored beer since the day I started using them.  It works like magic.  And I swear the tablets will probably last like 50 years.  I don’t see what a little age is going to hurt.

My 2 cents.

If kept dark, dry, and away from oxygen, your Campden should be good.  The reason you’d want to get fresh every year is that it’s difficult to keep dark, dry and away from oxygen.  Net, you have to make the judgement of whether or not you kept it that way.