Sourdough starter question

Sourdough starter question

My dad had a buddy back in World War II, a guy of Basque heritage, who used to do a lot of cooking and baking so they wouldn’t have to eat mess hall chow.  According to my dad, he used to make sourdough with a starter that was firm enough to remain in a little ball.  It was used to make the dough, then a chunk of the dough was broken off and saved in the flour sack until next bake.  Has anyone ever heard of doing this?  I’m just curious.  It seems like it’d dry out sitting in the sack.

Source: Fresh Loaf