The next step is to stack the celadon into a kiln. After it, the entrance is sealed and the kiln is ignited. The 2nd firing should be done nonstop for 2 days and nights with a maximum temperature of 1,3000oC
The firing is divided into five steps. The first is making fire, then peeling fire, third is raising fire, then melting fire, and lastly closing fire. There are various methods to measure the temperature, but usually it is done by intuition.
The important things estimating the temperature are the color of the fire, the color of the smoke, the sound of the fire, the mass of firewook, and the time.
The first making fire is to evaporate slowly the moisture and humidity within the kiln, and after complete evaporation, the soot should be stripped at the next stage. The slow burning first stage results in massive soot, so the next step should have greater fire to strip them. After the soot and black dirt are removed, the raising fire heats the Celadon until just before the melting point of the enamels.
During the late period of the raising fire, one should examine closely how the fire burns. If earlier Celadons were heated by thicker firewood from the main hole, now thin pieces of fire wood are put into each side hole of the kiln to melt enamels. During the closing fire the coals there were put aside during reduction are reinserted in order to prevent sudden drop of temperature.
Lastly, if the fire ends until the end hole, the kiln should be sealed and wait for 5~6 days until the kiln temperature drops under 30℃before retrieval.