Cacao Nibs can be added to the cold or hot-side of the brewing process. Like with a lot of spices, one must always be aware of the possibility of bacterial contamination. When adding to the mash or boil this is not an issue. But, when adding to the boil chocolate nibs should be added late in the boil to avoid bitterness. When adding to the primary, do it late in the fermentation process, so alcohol levels build up.