Hey Guys, looking to add coffee to my stout, post-fermentation. For those who do this, do you prefer adding whole beans or a coarse grind? And how much? I’m looking for a very coffee forward beer. I know some use cold brew, but that’s not what my heart is set on this go-round. Cacao nibs have already been added. Shooting for a finished product similar to Founder’s Breakfast Stout (hopefully better!).
The best luck I’v had was using whole beans in the boil. Not sure how much coffee flavor you will get at post fermentation temperature. However, if used in the boil, you can easily taste your way to the flavor you’re looking for.
Barely cracked, 5 oz in fermenter
Add at 0.4 oz/gal. You can crack or keep whole. Not super important but the more you grind beans, the faster you will extract flavor. A coarse ground I would test 12 hours out planning to rack off 12-24 hours out. Whole I would test around 24 hours planning on racking out 24-48 hours.
You can always go longer or make a second coffee addition. You can’t remove flavor if you go too much/too long. If you let the coffee sit too long you’ll start to extract tannins and flavors you might not want out of the beans.
Denny, this is exactly what I did! Added it 2 days before kegging, and the flavor and aroma were incredible when I kegged it. 
I always use whole beans in the fermenter after you reach terminal gravity. You will get all of the coffee flavor and minimize the amount of caffeine extracted from the beans. Usually two ounces of whole beans in 5 gals of beer for 3-4 days at room temperature is sufficient. But give the beer a taste after about 3 days to see if you need to go longer before packaging. You can then decide if you need to add a bit more more coffee beans or let it sit longer. The alcohol in the beer will kill any bacteria on the outside of the beans. I have been doing this in my coffee porter for years now and it works very well.
I use ~1 oz freeze dried Columbian in a little water to make a strong brew.
I use super coarsely cracked beans. I don’t like dark roasted because of the oils. I use 4oz/5g 3 days before packaging.