I've used powdered in chocolate stouts. Here are my thoughts on Hershey's cocoa powder:
- It's high in fat content, which means it kills head.
- It never completely falls out of solution, so you will have residual powder in every glass. I've let beers cold crash for over four months and it still won't fall out.
- Other than that, it's delicious.
I use about
1.5 ounces in a 5 gallon batch, added at 10 mins left in the boil for sanitation. I also use a half pound of chocolate malt in the recipe to add a roasted chocolate flavor. I've made it twice, and it tastes great but has a lousy, fast dissolving head (I have since named it "Headless") when bottle conditioned. I haven't tried kegging it yet but I will next batch I make.
Cacao nibs can lend that rich chocolate flavor without all the powder and fats spreading throughout the beer. There are some good chocolate stout recipes in the recipes section here and most people use them in a similar way, an ounce or two added to either the primary or in a secondary to age for a week or two (to taste).