I have an old family recipe for Chocolate chip cookies
2 ¼ cups flour
1 cup white sugar
½ cup brown sugar
1 tsp salt
1 tsp baking soda
1 cup shortening
1 tsp vanilla
Chocolate Chips as desired.
Add dry ingredients then wet ingredients to a large bowl, mix until well incorporated, seperate into golf ball sized dough balls, bake at 375°F for 8m15s
I want to make it into a chocolate chocolate chip cookie. I've followed advice from several online sources and just replaced about 1/4 of the flour with cocoa (so it's 1.5 cups flour , .75 cups cocoa). I've tried with both regular cocoa and dutch process and I really like the darker look of cookies that come out with the dutch process, however their texture isn't right. I have used this recipe and the flavors seem good, but I also want to get the texture right; the original recipe is very chewy, soft and moist, but the chocolate modification wound up much drier than I wanted.
After some research I found that the basic issue is that I've screwed up the PH of the recipe. I believe the fix involves substituting some or all baking soda for baking powder, but can't find a clear rule for how much. My guess would be since I'm effectively removing 1/4 of the acidic ingredients (flour, ph 6-6.8) and swapping them for ph neutral ingredients (dutch process cocoa), I should replace 1/4 of the baking soda with baking powder as well, but can't really find any information on how to go about replacing baking soda with baking powder or what ratio.
Edit: Upon more research I've also found that instead of modifying the baking soda I could just add some volume of cream of tartar, but I'm still not sure how to calculate this cost.