Smoked Rice Hull and Pottery

Padma Rajagopal with the organization SEED Trust in India wrote to us about smoked rice hulls as a planting medium for seedlings (EDN 69-5). She wrote, “I can add a hint about making the carbonized rice husk in another way, which would allow you to get something more out of the energy it’s burning. If there are local potters producing terracotta (low temperature unglazed pottery), they can make beads for jewelry, small decorative pieces, etc., and put them into a large fired pot alternating with thick layers of rice husk. This pot would be closed with a fitting lid and sealed with clay, then fired with other ware in the terracotta kiln until all the pottery in the kiln reaches red heat. As a result, the other pottery would be fired red, while that in the pot containing rice husk would fire deep matt black, sometimes with silvery effects from the husk as well—a process called reduction firing. If you burnish the pieces before firing, you’ll get a shiny deep black. The husk in the pot would be carbonized and can be used as per the instructions in EDN for raising seedlings.”