According to China Food Network: lye bread, a traditional German bread, is usually salty, and this is because of the use of lye water in the process of making lye bread. Lye water is an alkaline solution made by mixing water and baking soda. The main ingredient in baking soda is sodium bicarbonate (NaHCO3), which breaks down into sodium carbonate (Na2CO3), water and carbon dioxide in water.

During the baking process, the sodium carbonate reacts with acids in the dough, such as lactic and acetic acid, to produce carbon dioxide gas, which expands the dough and creates a unique taste and texture.

Lye bread usually has a savory taste and distinctive appearance and is a classic style of German bread.