On 1/12/2015 3:30 PM, Whitney Ryan wrote:

> I bought a ton of Baking Soda at Costco
> (sodium bicarbonate), and I want to make
> a small amount of baking powder.

You BOUGHT baking soda?

DIY BAKING SODA
<https://en.wikipedia.org/wiki/Baking_powder#Substitutes_for_baking_soda>
In times past, when chemically manufactured baking soda was not available, "ash water" was used instead. Ashes from hardwood trees contain carbonates and bicarbonate salts, which can be extracted with water. This approach became obsolete with the availability of purified baking soda.

re DIY BAKING POWDER (also obsolete)

<https://en.wikipedia.org/wiki/Baking_powder#Single_vs_double_acting_baking_powde rs>
"The acid in a baking powder can be either fast-acting or slow-acting.[7] A fast-acting acid reacts in a wet mixture with baking soda at room temperature, and a slow-acting acid will not react until heated in an oven. Baking powders that contain both fast- and slow-acting acids are double acting; those that contain only one acid are single acting. By providing a second rise in the oven, double-acting baking powders increase the reliability of baked goods by rendering the time elapsed between mixing and baking less critical, and this is the type most widely available to consumers today."

For the ingredients in some commercial baking powders see:
<http://whatscookingamerica.net/Q-A/BakingPowder.htm>

> Baking powder, as far as I can tell, is
> baking soda + cornstarch + "cream of tartar"
> which is usually either calcium phosphate
> or potassium hydrogen tartrate (KC4H5O6).

Calcium phosphate is not CREAM OF TARTAR (KC4H5O6)

<https://en.wikipedia.org/wiki/Potassium_bitartrate>
"Potassium bitartrate, also known as potassium hydrogen tartrate, with formula KC4H5O6, is a byproduct of winemaking. In cooking it is known as cream of tartar."
"A similar acid salt, sodium acid pyrophosphate, can be confused with cream of tartar because of their common function as a component of baking powder."

HTH

Susan
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