What is Soda Firing?

Soda firing is a form of atmospheric firing, meaning chemical elements are introduced to the kiln during firing. Very late in the firing, close to the final firing temperature of Cone 10 (2350° F), a mixture of sodium carbonate (soda ash) is added to the firebox. The soda ash vaporizes and is carried by the flame throughout the kiln, where it leaves its mark on the pieces and interacts with elements of the clay to form glaze. The distinctive marks that are left on the pottery indicate where the flames have touched the piece, giving each piece a truly unique appearance.