What is the optimum firing rate to use?

The optimum rate depends upon the thickness of the pots and clay type e.g. thin cast and grogged bodies can be fired quicker than thrown and ungrogged ones. Ideally, biscuit firings would be slower than 100C per hour up to 200C and 100 - 200C per hour beyond that point and ending with a short soak.

Glaze firings should be at 100-130C per hour but at 100C per hour maximum from 700-1100C with high carbon ball clay or fireclay based bodies.