Using a stone pestle to grind dried sweet potatoes in a stone mortar is more effective than using two stones, significantly improving efficiency.
South Stone Village originally had a naturally indented rock where Ma Lin initially tried to grind beans. But it was too inefficient, as the depression was shallow and narrow, uneven, and difficult to exert force.
The current stone mortar is handmade, making the depression more rounded, larger, smooth, and easier to apply force.
Using it to grind powder saves a lot of effort.
He continuously ground two pounds of bitter yam flour, feeling like it took less than an hour. It's probably because dried yams aren't as hard as beans or corn.
The kitchen aunt was very happy upon seeing this, tried it herself, and found it quite convenient.
To primitive people, this kind of stone mortar and pestle seemed magical.
