A Ball of Salt


What comes to your mind when you think of salt? Probably rock salt, sea salt, or table salt. But have you ever heard of Cibwa salt, from the Mpika district in the Northern Province of Zambia? What makes Cibwa salt unique is that it comes from grass!

The villagers living near Cibwa swamp perform a unique mineral-extraction process using tall grass that grows close to the Lwitikila River. They harvest the grass from August through October, before the rainy season starts. Once the rains begin, the grass does not yield any salt.

After the grass is cut and dried, it is burned in order to remove the organic components. The salt, though, does not burn. It remains in the ashes. The ashes are put into a container, such as a calabash, or gourd, and water is slowly filtered through the ashes. The water dissolves the salt and carries it through tiny holes at the bottom of the calabash. The resulting brine is collected for the next step​—evaporation.

Direct-heat evaporation is used to remove the water, a process that can take up to six hours. To do this, the brine is first poured into a clay pot and boiled on an open fire. More brine is added as the water evaporates. This produces a thick salt solution that eventually fills the pot. The pot now acts as a casting mold. When it is removed from the fire and then broken apart, a ball of salt remains.

Villagers have been making Cibwa salt for generations. No one knows who developed the process. It is amazing, however, that the same basic science behind modern salt processing is found in this remote part of rural Zambia​—far removed from the outside world.

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Calabash filtering the water

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Finished product

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Clay pot