Cocoa nibs are one of my favorite ingredients whether in brewing or in baking.
For me personally, 8oz in a 15 gallon batch is really not that much at all. It really depends on how much time you have to extract the cocoa goodness from the nibs.
I personally will use around 4-6ozs per 5 gallon batch. I let it sit until I get the cocoa flavor that I want, yup this means testing every few days.
It's similar to other adjuncts that you would add to secondary fermentation...
More nibs = less time to wait to extract, less nibs = more time to extract. I think however that they catch some people off guard because they give off a cocoa characteristic rather than a chocolate characteristic. Most people think of sweet, creamy, and fat when they think of chocolate. Wheras cocoa nibs have more coffee bean-like characteristics and in some cases a dry astringency.
I noticed that on a batch I left in secondary to extract for over 3 weeks that the nibs gave off a more earthy and soil-like complexity similar to tree-bark and red clay.
Also, I find that it's unnecessary to soak them in vodka or alcohol...usually by the time I add them to secondary my brew has already fermented out and the alcohol will be high enough to tolerate them.
What style of beer did you brew for them? What kinda gravity are we talkin about here?
cheers!
