Coming to the point of why I am writing this post:
I went to Costco couple of months back. I saw a big can of Dutch processed cocoa for a very good price and bought it. I was talking to one of my friends about this, who happens not to be a baker, yet. This friend of mine does bake some brownies or chocolate cake for her daughter occasionally. So, she went ahead and bought the same. What I forgot to tell her when I told her about it was - this is not the same as natural cocoa. You cannot interchange these two in a recipe unless you know how to adjust the other ingredients.
So, what is dutch processed cocoa? This is cocoa powder made by using a process called dutch process which is basically treating the cocoa with an alkalizing agent. This in turn reduces the acidity of the cocoa, makes it milder in chocolate flavor and reduces the bitterness of chocolate to a very good extent. It is also reddish in color compared to the brown of natural cocoa.
I said you can't use these two interchangeably. Reason being dutch processed cocoa does not react with baking soda to raise the cake batter. Dutch processed cocoa should be used in a recipe which has baking powder as a leavener not just baking soda. That being said, if the recipe has highly acidic ingredients in it along with baking soda, you can use dutch processed cocoa in place of natural cocoa.
Dutch processed cocoa is used extensively in chocolate drinks, ice creams and where a mild flavor of chocolate is preferred over high chocolate flavor of natural cocoa. It doesn't clump as much as the natural cocoa.
They say chocolate is good for you. Right? Comparing these two in the line of 'good for you', dutch processed cocoa looses all of its anti oxidants during the process. Whereas natural cocoa has a good percentage of anti oxidant from the cocoa beans. Taste wise, I think I like dutch processed cocoa better since I don't like the bitterness of the natural cocoa.
Couple of tips how to interchange the cocoa powder to replace the baking chocolate bars (from Cake bible by Rose Levybaum)
1 Oz bar of bittersweet or semisweet chocolate :
(1 TBSP + 1 3/4 tsp) (9.5 grams) of cocoa natural cocoa + (1 TBSP + 1/2 tsp )(14.5 grams) of granulated white sugar + 1 1/2 tsp (7 grams) of unsalted butter.
Dissolve the cocoa in at least 1/4 cup (60 ml) hot liquid to bring out the cocoa's full flavor.