It's all a white powder.

No matter what I mix into the dough, it grows as desired.

Some recipes contain baking soda or baking powder. Gingerbread screams for potash, in an organic recipe I find potassium bitartrate 🙈

What is the difference?

Baking powder is a mixture of a leavening agent, usually sodium hydrogen carbonate (sodium bicarbonate) or potassium hydrogen carbonate, and an acidifying agent often containing phosphate, such as disodium dihydrogen diphosphate (E 450a) or monocalcium orthophosphate (calcium dihydrogen phosphate) (E 341a) or a phosphate-free alternative such as potassium bitartrate an acid carrier.

In addition, a release agent made from corn starch, rice starch, wheat starch or wheat flour is added to bind moisture and thus prevent premature CO2 evolution.

Potassium bitartrate is formed during the storage of wine or grape juice. When it crystallizes, it is deposited mainly at the bottom of the container, e.g. a bottle, or on the bottle cork. in combination with sodium hydrogen carbonate, it is used as a leavening agent for baking.

Astonishing fact is, that baking is only a fraction of the possible applications of "baking powder".

It is used in pharmaceuticals, cosmetics, chemicals, paint production, medical technology, cleaning agents, plastics production, animal feed and other solutions.

The list is long.

Check it here