You use them all in baking, but what 's the difference?
Yeast, sourdough and baking powder are used to raise dough. They provide for the production of carbon dioxide which remains in the dough as bubbles.


Baking soda is soda bicarbonate. It is sometimes confused with baking powder. Both are chemically synthesized products.
Baking powder mainly ensures that gas is being formed (in order to bring about a rise).
Baking soda has an effervescent effect, this means that the formed gas is retained.

Baking powder contains some substances, usually only a carbonate and an acid. If a carbonate comes into contact with water and an acid, it will decompose into various components, in which also carbon dioxide is created. This is not resulting in other flavors and fragrances, the taste of the product will therefore not be affected.

Baking powder contains some substances, usually only a carbonate and an acid. If a carbonate comes into contact with water and an acid, it will decompose into various components, in which also carbon dioxide is created. This is not resulting in other flavors and fragrances, the taste of the product will therefore not be affected. 

Other leavening agents

Cream of tartar (KC4H5O6)

Potassium bitartrate, potassium hydrogen tartrate, potassium acid tartrate, monopotassium tartrate, cream o tartar. Do not confuse with tartaric acid, or potassium tartrate, because that is H2C4H4O6.

Tartar often forms "the acid component" in baking powder.

Ammonium bicarbonate (NH4HCO3)

Ammonium bicarbonate, bicarbonate or ammonia, ammonium hydrogen carbonate, heartshorn, hornsalt, smelly powder, AmBic, powdered baking ammonia.

In the West it is still used as a leavening agent in flat biscuits, crackers and egg cakes, in China in steamed buns and almond biscuits.

A penetrating ammonia odor may remain in the product. That is why it is probably rarely used.

No leavening but a cleaning agent: soda (Na2CO3)

washing soda, sodium carbonate, soda crystals, soda ash, soda carbonate.

Used to clean dirty pans and such things, not really a function (anymore) in our food.