It is also a standard food preservative. I drank a litre of it once by
mistake in the very early days. One reason why I stress that chemicals
should always be properly labelled and kept in appropriate containers.
Incidentally bicarb is the neutralising agent in stage two of the peroxide
recipe for making ferric oxalate. The CO2 given off there is profuse but
unlikely to cause harm. The stage where the exothermic reaction is strong
enough to bend heavy duty plastic stirrers is more interesting though. But
even then the method is probably less complicated in terms of both chemical
reactions and practice than many culinary recipes.
Using potassium metabisulphite makes me cough like crazy especially when
making the lye part of the acid amidol formula. Bob Schramm tells us that
he makes his on his front drive.
Terry King
Terry King