"Cream of tartar": gereinigter Weinstein, doppelweinsteinsaures Kali.
Hierzu einige Auszuege aus amerikanischen Echos:
From: sbhattac@db.Gba.Nyu.Edu (Shankar Bhattacharyya) Subject: Re:
Baking powder vs. Baking soda [...] Baking powders, by contrast, also
contain a dry acid, usually one of a variety of acidic calcium
phosphates, or else potassium hydrogen tartarate, commonly known as
cream of tartar, and some other stuff to keep it from [...] The acid
phosphates and potassium hydrogen tartarate are used because they are
among only a few convenient solid acids which are acceptable in baked
goods. There are alternative acids available, but these are at least
common. [...]
From: szfawl@hamlet.ucdavis.edu () Subject: Re: What is Cream of
Tartar ? [...] Tartaric acid is a by-product of the fermentation
process. Tartaric acid is known as a "diacid" (pronounced dye-acid)
since it has two acid groups. Cream of tartar is made when one of
these acids has been neutralized and substituted for by potassium.
Cream of tartar is therefore the potassium salt of tartaric acid and
it is weakly acidic. Cream of tartar is also found in most baking
powders along with baking soda and sodium aluminum sulfate. Cream of
tartar is commonly used in the beating of eggs. It's action is to
change the pH of the albumin slightly and to stabilize the foam. To
understand how stabilization occurs you only need to know that
albumin is made of proteins and proteins are made from acids (amino
acids). Whipping eggs breaks these proteins apart and they don't like
this very much and try to get back together. Cream of tartar keeps
this from happening by providing a suitable acid medium to keep the
proteins from coagulating (reforming their bonds). Thus eggs beaten
with tartaric acid keep their loft. More is not better, only 1/16th
of teaspoon is recommended per egg white. [...]