Talking about Ancient Times in Yangcheng ⑬| How technical are the green bricks of the Xiguan House?

When you think of Xiguan House, what do you think of? The quaint gate? A colorful Manchurian window? When walking through the Qingyun Lanes, will you ever wonder how these beautiful blue bricks are fired? What kind of knowledge and skills are contained in it?

The main hall of the Xiguan House restored by Xiguan Folk Museum. The main hall is mainly used for family gatherings, worshiping ancestors and receiving important guests.

The art of making clay bricks is all in the details

See the question \”How are the green bricks of Xiguan House fired?\” , you may laugh out loud in your heart: \”Just tell me The craftsmanship of the gates and Manchu windows is remarkable, I still believe it. Just bake a brick, what’s so hard about it?”

If you really think so, what’s the problem? To be an apprentice in a brick kiln next to the river in Guangzhou during the Qing Dynasty was to ask for good fortune. The first step in the process of making green bricks is to get soil. If you take a pile of soil from the river and the master touches it, it is not sticky at all and there is still sand in it. He will definitely be furious with you: \”Burn green bricks. The soil should be sticky but not loose, powdery but not sandy, what kind of soil are you looking for!\”

It turns out that even the acquisition of soil for firing the green bricks used to build a big house is very particular. The clay that is \”sticky but not loose, powdery but not sandy\” cannot be made into bricks immediately. People have to fill the water first and then pedal in an even rhythm. After this \”tap dance\” step, the moisture content of the soil will be even, and the fired green bricks will have a dense texture.

The trampled brick mud has even water content and fine texture, and can be used to make bricks. To make bricks, the sticky soil is beaten into long cubes, and then placed in wooden molds for \”shaping\”. Then the wooden molds are removed, and the bricks are dried before being fired in the kiln. However, when demoulding, the bricks are still very soft and a corner may be broken off accidentally. When drying the bricks, if you forget to cover them evenly with a layer of straw, the bricks will crack a few more times when the sun shines… all the previous efforts will be in vain.

It takes a lot of effort to pour water into the green bricks when firing them

After the bricks are dried, they are put into the earthen kiln and the heat is controlled to produce beautiful and hard bricks. Green bricks are the last step in the entire brick-making process, in which the heat is the most important.Pay attention to it. Without hard study and training, the entire kiln of bricks will be burned to waste if you are not careful.

As early as two thousand years ago, Guangzhou people had learned to bake bricks, but the technology of firing green bricks gradually became mainstream after the Song Dynasty. The tomb bricks from the Eastern Han Dynasty excavated by archaeologists come in various colors such as dark red, gray-red, red and yellow, etc. The colors are very mixed. Compared with the elegant blue bricks of the Xiguan House, the color is not the slightest bit different. Unlike fired red bricks, fired green bricks require manual intervention. When it is almost \”cooked\”, water is slowly poured into the kiln from the top of the kiln, and the water slowly seeps down. When encountering high temperatures, it quickly turns into water vapor, and fresh air cannot enter, and the reducing flame sings in the kiln. Without the main character, the oxidation reaction is not sufficient, and the iron element in the brick is converted into divalent iron, and what appears is a beautiful blue-gray color. The apprentice lights the fire while the master pours water. When the water is almost filled, the kiln is sealed and the firing process is completed. The cooling time of green bricks is much shorter than that of red bricks, and the production efficiency is greatly improved. In addition, their corrosion resistance is much higher than that of red bricks, so they are naturally more popular in the market.

Of course, no matter how experienced the masters are, they cannot understand the principles behind these crafts. They just try again and again, improve again and again, accumulate experience from generation to generation, and pass it on from generation to generation. Without their unremitting efforts and attempts, how could we appreciate such a simple and elegant Xiguan House?

Text/Guangzhou Daily New Flower City reporter: Wang Yuehua

Photo/Guangzhou Daily New Flower City reporter: Su Junjie

Guangzhou Daily New Flower City editor: Zhao Xiaoman

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