What if you would like to change from one chocolate to another...
The cocoa butter makes the texture of your recipe, not the taste, which is brought by the dry extract of the cocoa! The cocoa butter has a structural role, and it fixes the flavor as well, like any fats!
The percentage written on a packaging indicate the amount of "cocoa material" inside the chocolate
Cocoa material = Cocoa Butter+ dry extract from the bean
The rest of the percentage is the others ingredients, sugar, lecithin and vanilla...
Cocoa butter is called, the "cement of pastry chefs", it gives the structure, fixes the flavor and makes the ganache set!
In order to balance a recipe, only base your calculation on the cocoa butter percentage
1000 g of Araguani at 44 % of cocoa butter
X g of Guanaja at 42,5 %
(1000 X 0,44)/ 0,425 = 1035 g
The result is logical as we replace by a chocolate with a lower cocoa butter content, so in order to have the same texture, we will use less chocolate
This technic works really well with any brands as far as you know the exact cocoa butter content (the chocolate maker should be able to provide it to you!)
Difficult to change from a dark chocolate to a milk chocolate using this method!
If you want to learn more, I made a course about this, in depth tempering explanation...