Morgan you have just about made my heart stop...
Haha All this time I have been making things with baking powder and counted it as a 0. Never thought to check this for those hidden carbs.
Thank goodness I don't use too many baked goods on a regular basis! After doing some research I see that the carbs are more than likely coming from the cream of tartar and of course the cornstarch that they add in to protect against moisture and to keep it from caking up before you can use it. As you mentioned you can make your own at home to save some of the carbs but it's not by much. The recipe that I found will make just over 1/3 cup or 6 Tbsp :
Homemade Baking Powder
1/4 cup Cream of Tartar
2 Tbsp Baking soda
Put through a fine sifter and store in an airtight container. Be sure to sift again before using after storing. An interesting note...did you know that cream of tartar is a byproduct of the winemaking process as the powder forms inside wine barrels during fermentation?
According to the National Nutrient Database here
http://ndb.nal.usda.gov/ cream of tartar is 1.84 carbs per tsp, at 12 tsp per 1/4 cup, that makes this whole recipe 22.08 net carbs. So if you needed to use 2 Tbsp in a recipe it would be 1/3 of your mix from above adding 7.36 net carbs to this bread recipe. MAN!!! I am so crushed!!
Obviously the store bought baking powder with the cornstarch mixed in would be higher but still...... I will definitely be investigating the art of using vinegar with the baking soda as a leavening agent in my baked goods
http://www.ehow.com/how_8678161_use-vinegar-leavening.html This goes to show how even someone that has been doing FTS for a while can have carbs slip through the cracks....sneaky little buggers
I'm off to cry myself to sleep now