Isn't it always just the way... you begin a recipe knowing that your staples in the pantry are all where they should be, and when you go to reach for something the jar is empty due to some teenage girl making cookies and spilling the remaining amount of baking powder and not telling you. Add the fact that it's December 23rd at 6 PM and the thought of running out to the store along with the rest of the shopping world is about as appealing as visiting the penguins in the Antarctic, and one learns to get crafty.
Who knew that adding NaHCO3 to KHC4H4O6 in a recipe would give the reaction KNaC4H4O6 + H2O +CO2 thereby making a mad dash to the store unnecessary? If that makes no sense to you, you are not alone. As my chemistry days in 11th grade earned me the lowest grade in my entire school history, the only thing making sense to me is adding the H2O.
Apparently, in real words, Baking Powder is made up of an acid, a base and some sort of filler. Keeping the ingredients on the list dry allows one to store the mixture in the pantry, and it's only when the ingredients are mixed with liquid, and again heated, that they react giving us the rise that we love in our muffins, pancakes, biscuits, etc.
In the most common combination of ingredients for homemade baking powder, your base is baking soda (sodium bicarbonate), cream of tartar (potassium bitartrate) is your acid, and corn starch becomes your filler. Baking soda activates at high temperatures and combining baking soda with and acid, like cream of tartar, activates it even earlier when combined with liquid giving us - Double-Acting Baking Powder. The corn starch is added simply to keep the combination from absorbing moisture (like humidity) before using.
Researching homemade baking powder brought almost the same measurements and ingredients in nearly every recipe I found online, but it did leave me wondering... what the heck is cream of tartar? Cream of Tartar is actually a natural ingredient and a byproduct of wine making. A white, odorless powder, the ingredient is formed from the sediment remaining in wine barrels after the wine is processed. Interesting fact... cream of tartar has been found in ancient pottery dating back over 7,000 years.
So whether you are simply making a batch because of that darn teenage girl, saving a bit of money by DIY, or ensuring that your baking powder is aluminum free (aluminum has been linked to Alzheimer's and may also leave a metallic taste in your baked goods), making baking powder at home is a piece of cake.
Homemade Baking Power - DIY
Baking soda is inexpensive and easily found at any market as is corn starch. Cream of Tartar can usually be found in the spice section of grocery stores, but can also be purchased less expensively and in bulk from numerous online source such as Penzey's, Amazon, and one of my favorite online spice shops, The Spice House.
Use this handy recipe scaling calculator to multiply your batch, but the ratio is basically 2:1 (2 parts Cream of Tartar to one part Baking Soda and one part corn starch)
For 1 tsp baking powder mix:
1/2 tsp cream of tartar
1/4 tsp baking soda
1/4 tsp corn starch
For 1 TBS baking powder mix:
1 1/2 tsp cream of tartar
3/4 tsp baking soda
3/4 tsp corn starch
Liv Life Note: I have used the above versions with success, however I have read that you may leave out the corn start if using immediately...