Making pottery is fun, but the kiln is where the magic happens. You put in a piece made of dry mud, and it comes out as solid stone.

In our Pottery and Workshops studio, the kiln is the final step that turns a raw pot into finished pottery. Here’s what happens inside the kiln, step by step.

1. Removing Hidden Water

 

Even when a pot feels dry to the touch, it still holds microscopic water deep inside the clay. 

As the kiln slowly heats up, this water turns into steam and escapes. If the temperature rises too fast, the steam gets trapped and builds pressure, causing the piece to explode.

This is why we use a “candling” stage keeping the heat very low for hours to ensure every last drop of moisture evaporates safely.

2. The Point of No Return

 

At around 900°C, a permanent change occurs called vitrification.

The silica (sand) inside the clay begins to melt slightly and bond the other particles together, like tiny pieces of LEGO fusing into one solid block.

From this moment on, the piece can never return to mud. It’s like baking bread, once the heat transforms the dough, you can never turn it back into flour again.

3. Turning Powder into Glass

 

If a piece is glazed, it goes through a second firing to reach its final look.

Glaze is made of minerals and glass-formers that look like dull powder when dry. Inside the kiln, these minerals melt into a liquid.

As the kiln cools, that liquid “freezes” into a solid, shiny layer of glass. This makes the pottery beautiful, colorful, and 100% waterproof.

 4. How the Air Affects Color

 

The atmosphere inside the kiln also changes the final chemical reaction of the minerals

Oxidation (Plenty of oxygen): The metals in the glaze (like copper or iron) react with oxygen to stay bright.

Reduction (Limited oxygen):  The fire “starves” for air and pulls oxygen out of the clay itself. This changes the chemical makeup of the minerals, turning greens into deep reds or creating metallic finishes.

Conclusion

The kiln is where the hard work pays off. By using extreme heat to change the clay’s chemistry, we turn simple earth into something beautiful and permanent. It is a mix of science, patience, and tradition that ensures every piece is strong enough to last a lifetime.

Ready to see the transformation for yourself? Join us at Pottery Class Marrakech to get behind the wheel and create your own ceramic masterpiece.