I’m hoping to brew either an oatmeal or milk stout soon with coffee in it... I’m aware of many ways to add the coffee but onl want to consider 2. I will cold brew the coffee and then either 1- add into the boil. This will boil off oils from the coffee which may affect head retention by will it make the coffee bitter (ie make the cold brewing of the coffee pointless)? Or 2- add into fermenter post active fermentation a few days before bottling/kegging. Worried that this may have an adverse affect on head retention due to coffee oils? Mikkeler book of beer basically follow option 2 above..... Any thoughts??