Even with the omission of any discussion of the eleventh-century inland salt-production centres of Worcestershire and Cheshire, a review of coastal production in the Norman period is a considerable exercise. It may be thought unnecessary: adequate summaries would appear to exist, notably in the three regional volumes of The Domesday Geography and in Professor Darby’s Domesday England. However, salt production may be understood more satisfactorily by using a broader chronological perspective and considering in more detail the uses to which salt was put. Within the constraints imposed on the Domesday Geography, the evidence for salt-working assembled in those volumes is confined almost entirely to an analysis of numbers of salinæ, and their renders, accompanied by distribution maps showing the numbers of salinæ recorded. Darby, in his concluding remarks for the volume on Eastern England, states

In this review an attempt will be made to expand the evidence published so far and provide what information there may be for the details omitted from the Domesday Book.

It is necessary, first of all, to establish to what uses salt was put in the mediaeval period. In Ælfric’s Colloquy the importance of salt is neatly summarised and refers to salt as flavouring food and that, without it, butter and cheese would perish. One may assume that butter- and cheese-making techniques change little: Bridbury records that on one of the bishop of Winchester’s estates in 1305 one pound of salt was needed for the production of every ten pounds of butter or cheese.