I used cacao nibs in an experimental Chocolate Porter last year. I split the batch into 4 one gallon jugs for secondary and pitched a different level of nibs in each.

To start with I bought raw nibs before I learned that they should be roasted to bring out the flavor. So my first task was an experiment in roasting cacao nibs. After trying three different temp/time combinations this is where I landed. One roasting method suggested roasting at 150 F for 10 minutes then 120 F for 10 minutes. I may be wrong but that does not sound much like "roasting" for me, so I assumed that the temps were really in C instead of F. This translated into the following:

- 300F for 10 min.
- 250F for 10 min.

After roasting I weighed out the nibs for the following pitching rates:

- 1 oz./5 gal. = 0.15 oz.
- 2 oz./5 gal. = 0.30 oz.
- 3 oz./5 gal. = 0.45 oz.
- 5 oz./5 gal. = 0.75 oz.

I added just enough vodka to cover the nibs and let it soak for about 10 days. After soaking the vodka/nib mixture was dark brown and smelled awesome, like chocolate cake. I pitched the vodka and nibs into each secondary jug.

Initially after carbonation the 3 oz./5 gal. was the best in terms of chocolate aroma and flavor without bitterness; 5 oz./5gal. was a little bitter. However, after a month or so the bitterness in the 5 oz. sub-batch subsided and it became the favorite.