Beans

The Oxford Companion to American Food and Drink

To avoid the curse of underdone beans along the gold rush trail, portable soup became the saviour of the hour. Beans and bear grease were stewed to tenderness on the stove; then the kettle was allowed to freeze. Next, the soup was dumped from the pot in a lump and stored in a burlap sack. When dinner was needed an ax was applied to the lump, and a few chunks were thawed and heated.