Saltglazing is a method of producing a glaze from the clay surface of the pot during the firing, rather than, as is normally the case, by applying a glaze as a separate liquid material onto a pot’s surface before it is fired. To do this the potter introduces salt (sodium chloride) into the fireboxes of the kiln towards the end of the firing at round about 1260°C. The salt volatilises and the sodium from the resultant vapour travelling through the kiln with the flame, combines with the silica in the surface of the pot, in effect ‘melting’ the surface into a thin layer of glass, i.e. the glaze.

Saltglazed pottery first appeared in the Rhineland in the 14th century and the technique is thought to have originated from local potters using wood from containers carrying meat or fish preserved in salt to fire their kilns. The development of saltglazing as a process used by industry into the 20th century and by studio potters over the last fifty years or so is well described in Rosemary Cochrane’s book ‘Salt-Glaze Ceramics’ (The Crowood Press, 2001)