Soda firing is a kiln technique where sodium carbonate (soda ash) is introduced into the kiln at peak temperature, around 2,300 degrees F (cone 10). The sodium vaporizes and bonds with silica in the clay surface, creating a glassy coating without any hand-applied glaze. No two pieces come out the same.

What is the difference between soda firing and salt firing?

Salt firing uses sodium chloride (table salt), which produces a distinctive orange-peel texture but releases hydrochloric acid, hard on kilns and the environment. Soda firing uses sodium carbonate or baking soda, producing smoother, more varied surfaces without toxic gases. Most contemporary ceramic artists have shifted to soda.

Why are soda-fired ceramics more expensive?

A full soda firing cycle runs roughly 36 hours. Experienced firers keep only 60 to 80 percent of a kiln load. Kiln placement is an art that determines each piece's character. And there are no do-overs: a soda-fired piece is exactly what the kiln made it.

How does soda firing create variation on a single piece?

Soda vapor travels on the flame path and does not land evenly. Pieces near the ports get hit harder. Pieces sheltered behind others get less. The side of a bowl facing the flame looks completely different from the side facing away, all from the same firing.