1) A tun or large barrel to contain bolted flour or perhaps bran, that is ‘boltings’ (OED).
1335 unum magnum doleum pro bultynges, Ripon
1485 unum bultington, vjd, Ripon
1535 ij bowlting tonnes ijs viijd, Stillingfleet
1574 In the backe howse. One boltinge towne, ij kneading trowghes, iij tubes, Brough. Similarly: c.1450 j bultyngfat cum coopertorio viijd, Beverley
1563 Item, a boultinge tubb, a kneading trough, with other implementes 3s 0, Elmswell.