When using unsweetened cocoa in a recipe calling for dutch-process, you need to adjust the amount of baking soda you use . ..
Here's a explanation: http://www.cupcakeproject.com/2007/05/dutch-processed-cocoa-powder-new-pantry.html
"Substituting Unsweetened Cocoa for Dutch-Process Cocoa - 3 tablespoons (18 grams) unsweetened cocoa powder plus a pinch (1/8 teaspoon) baking soda.
Substituting Dutch-Process Cocoa for Unsweetened Cocoa - Leave out any baking soda called for in the recipe."

Dutch cocoa is processed with alkali, which gives it a different flavour than regular unsweetened, though are you talking Hershey unsweetened or some other cocoa. I think Hershey has a strange back ground flavour and have never really liked it.

You need to make a hot chocolate with Dutch (Droste is the standard) and another chocolate to see the difference before you cook with them.

Found the answer below. Sorry...should have searched first.