Hi Jerry, here's a surprise: Yesterday's brew had no chelating agents! I guess I didn't make that clear, but I wanted to see whether it would die quickly with no protection against Fe/Cu ions. Thanks for the note about oxidation of ferrous sulfate. I transferred it to a little amber glass bottle last night, so hopefully it'll keep a while. Anyway, do you know of anything else that would cause the purple? I used distilled water, so there should be no unknown chemicals in there.
Originally Posted by Gerald C Koch