I recently made a chocolate coffee porter, and added the coffee to the secondary, as well as the cocoa nibs. I added the cocoa nibs first after crushing, toasting and soaked in vodka for 1 week. The chocolate extract tasted great and i added the vodka too. 1/2 pint or so. I then waited 7 or 10 days before adding the coffee. I steeped 4 ounces of French roast in a quart jar full of water overnight, and added the coffee the next morning, as that was my bottling day. I didn't think there was enough coffee flavor with the steep water I added, so I put another quart of water on the coffee grounds, shook it up, and poured that water into the secondary too. I wondered at that point if the coffee would now be overpowering. Yup, it was. Way too overpowering, I mean you could add cream and sugar and sell it as a cold coffee beverage. Fortunately my wife likes it, as I just can't drink them anymore. I guess my whole point here is what I have heard so many times; if your beer tastes strong enough now, it will be too strong. Or so it was for me. Don't get me wrong, I will make another on a day, just one I am not forced to bottle that same day.