For a longer section on a related group of chemicals with much common history, see
Potash § History.
Potassium carbonate is the primary component of
potash and the more refined pearl ash or salts of tartar. Historically, pearl ash was created by baking potash in a
kiln to remove impurities. The fine, white powder remaining was the pearl ash. The first
patent issued by the
US Patent Office was awarded to
Samuel Hopkins in 1790 for an improved method of making potash and pearl ash.[5]
From the solution crystallizes the
sesquihydrate K2CO3·3⁄2H2O ("potash hydrate"). Heating this solid above 200 °C (392 °F) gives the
anhydrous salt. In an alternative method, potassium chloride is treated with carbon dioxide in the presence of an
organic amine to give
potassium bicarbonate, which is then
calcined:
in
cuisine, where it has many traditional uses. It is used in some types of
Chinese noodles and
mooncakes, as well as Asian
grass jelly and Japanese
ramen. German
gingerbread recipes often use potassium carbonate as a baking agent, although in combination with
hartshorn.
^CRC handbook of chemistry and physics: a ready-reference book of chemical and physical data. William M. Haynes, David R. Lide, Thomas J. Bruno (2016-2017, 97th ed.). Boca Raton, Florida. 2016.
ISBN978-1-4987-5428-6.
OCLC930681942.{{
cite book}}: CS1 maint: location missing publisher (
link) CS1 maint: others (
link)
^
abH. Schultz; G. Bauer; E. Schachl; F. Hagedorn; P. Schmittinger (2005). "Potassium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH.
doi:
10.1002/14356007.a22_039.
ISBN3-527-30673-0.
^See references to "pearl ash" in "American Cookery" by Amelia Simmons, printed by Hudson & Goodwin, Hartford, 1796.
^Civitello, Linda (2017). Baking powder wars: the cutthroat food fight that revolutionized cooking. Urbana, Illinois: University of Illinois Press. pp. 18–22.
ISBN978-0-252-04108-2.
^Leonard, J.; Lygo, B.; Procter, G. "Advanced Practical Organic Chemistry" 1998, Stanley Thomas Publishers Ltd
^Child, Lydia M. "The American Frugal Housewife" 1832