Baker’s yeast is a living and active product, a microscopic fungus which allows the dough to ferment (by producing gas), to develop aromas. Only baker’s yeast makes it possible to obtain bread products: bread, pastries, pizza doughs. Baking powder is composed of bicarbonate of soda, potassium hydrogen tartrate and corn starch and does not allow fermentation, so it doesn’t allow to bake bread. It is used for making cakes. If you wish to bake bread at home, you will need to use baker’s yeast.