The small room you pass through to get into the undercroft is called the buttery, and was used to store drink and prepare simple food. The monastery kitchen was at this corner of the site, just the other side of the wall.
The fact that the ceiling in this room is so well finished probably indicates that this was originally more than just a store room. It may have been a parlour before the Western Range was built, or a dining room for guests. Unlike most of the Birkenhead Priory site, it is possible to see the original floor level. The stone floor is still visible either side of the present timber walkway, which was installed when the Priory museum opened in this space in the late 1980’s. A spiral staircase leads up the Refectory.