St Osyth's Priory, Brewhouse and wall between Brewhouse and West Barn

St Osyth's Priory includes a brewhouse with a 16th-century base, altered in the 18th century, and a section of wall connecting it to the West Barn. A 19th-century lean-to has been added to the north side.

The original structure’s base is constructed from limestone and septaria, with flint-galletted mortar and limestone quoins. The upper walls are red brick in English bond, while the north wall of the lean-to is weatherboarded. It has a pitched tile roof. The connecting wall is built from stone, septaria, tile, and brick.

The brewhouse is rectangular and divided in two, running lengthwise, with the lean-to projecting to the north. The earlier, south part of the building is two stories high. The south elevation has a central entrance with a round stone arch containing a keystone and plank and batten door. The ground-floor stonework extends almost to the top of the door jambs, and two small windows are set within the brickwork either side of the entrance. To the west of the entrance, there’s a low arched opening with stone quoins, a brick arch, and a plank door. Towards the east end of the first floor, there’s a full-height opening, with a smaller window to its west. Set into the west elevation's stonework are two bricked-up openings with brick arches and stone quoins; an inscription 'SED 1898' is set in stone between them.

The roof slopes down from the ridge of the original structure to the low, weatherboarded north wall of the 19th-century lean-to. The gable end of the brewhouse is formed by a wall constructed from stone, septaria, tile, and brick, showing considerable patching and repair. It adjoins the south gable of the West Barn. Near the north end of this gable wall is a small blocked opening, the west face of which has a chamfered limestone surround above a limestone band.

Inside the lean-to, a section of the original stone and septaria wall is visible. A chamfered brick arch has filled an opening in the wall at the west end. Opposite the arch, in the north-west corner, there's a square brick structure housing a small hearth with a cast-iron grate and a lidded copper. The roof in the earlier south portion of the brewhouse features coupled rafters and collars. A rubble partition wall separates the west end of the ground floor from the rest of the building.