[Sca-cooks] baking powder

[Decker, Terry D.]

Baking powder was initially sodium bicarbonate (baking soda) mixed with
cream of tartar and an inert starch filler (corn starch is common in the
U.S.).  Later, in some baking powders, the cream of tartar was replaced by
an acid phosphate (monocalcium phosphate is one of those still in use) to
provide a more controlled release of carbon dioxide.

These are "single action" baking powders, where the chemical rise occurs "on
the bench" as the ingredients are mixed and shaped.

Some baking powders have replaced the phosphate with sodium aluminum
sulfate, which will initiate a chemical rise during the mixing, then
initiate a second rise at oven temperatures (140 F or 60 C comes to mind).
Baking powders which give this double rise are "double action" baking
powders.

Usually, baking powders are marketed without regard to the "single action"
or "double action," but Rumsford (a phosphate/bicarbonate single action) is
beginning to use the possibility aluminum ingestion is related to
Alzheimer's to market against Calumet and Clabber Girl (sodium aluminum
sulfate/bicarb double actions).

Bear

> I've managed to delete the original post, but there was a reference to
> 'single-' and 'double-acting' baking powder.
>
> I've only ever seen one sort of thing marketed here (Lochac)
> as "Baking
> powder"...bicarb. soda plus a phosphate aerator, plus a
> filler, usually
> rice flour. Four teaspoons of it make a pound of plain flour into a
> pound of self-raising flour. Is this 'double-action', and
> bicarb. alone
> 'single-action'?
>
>
>
> Margaret/Emma