Starsan + Campden = Sulphur ???

Hi,

For my brew session yesterday I picked up some Campden tablets to treat the chlorine/chloramine in my water. I also started using StarSan for the first time. Of course, being ultra-paranoid after a small chlorophenol off-flavour in my last beer, I mixed the StarSan with the treated water. Not long after, I noticed a distinct sulphur smell coming from the solution.

I've read here that sulphur treated gloves produce a strong sulphur odour when working with StarSan. I'm wondering if the sulphites in the Campden tablets would do the same.

Any chemists out there care to explain?

Thanks,

Brian

http://en.wikipedia.org/wiki/Potassium_metabisulfite

"Potassium metabisulfite, K2S2O5, is a white crystalline powder with a pungent sulfur odour..."

How many tabs did you use for how many gallons of water? I use 1/2 tablet per 5g to remove chloramines. My star san is usually mixed with distilled water.

I used a bit more I guess. Total water treated was around 55 litres to which I added one full tablet. So that's around 14.5 gallons for one whole tablet. Thinking back, I should probably have used only a half, but I don't think there is any harm done. At least I hope not.