According to my observation, rural cauldrons need to be scrubbed clean, then dried, added with a spoonful of oil, and moistened by the oil. Most of the reasons for the dark color are related to this.

Second, the pot should be boiled with water, and the hot pot paste cake can solidify quickly, and the firepower should be strong. The situation you mentioned will occur at low temperature, and the hot pot will produce a certain yellow gab when heated quickly. If the temperature is not enough, the color will be dark and the gaba will not be brittle, which means it is related to firepower.

Third, stick the cake near the bottom of the pot, where the heat is concentrated, so the effect is good.

I hope my answer can help you.